diff --git a/src/Compiler/Service/ServiceParseTreeWalk.fs b/src/Compiler/Service/ServiceParseTreeWalk.fs
index a1d674e2fb6..025ab8a665d 100644
--- a/src/Compiler/Service/ServiceParseTreeWalk.fs
+++ b/src/Compiler/Service/ServiceParseTreeWalk.fs
@@ -25,6 +25,11 @@ type SyntaxNode =
     | SynMemberDefn of SynMemberDefn
     | SynMatchClause of SynMatchClause
     | SynBinding of SynBinding
+    | SynModuleOrNamespaceSig of SynModuleOrNamespaceSig
+    | SynModuleSigDecl of SynModuleSigDecl
+    | SynValSig of SynValSig
+    | SynTypeDefnSig of SynTypeDefnSig
+    | SynMemberSig of SynMemberSig
 
 type SyntaxVisitorPath = SyntaxNode list
 
@@ -184,6 +189,28 @@ type SyntaxVisitorBase<'T>() =
         ignore (path, attributes)
         None
 
+    /// VisitModuleOrNamespaceSig allows overriding behavior when visiting module or namespaces
+    abstract VisitModuleOrNamespaceSig: path: SyntaxVisitorPath * synModuleOrNamespaceSig: SynModuleOrNamespaceSig -> 'T option
+
+    default _.VisitModuleOrNamespaceSig(path, synModuleOrNamespaceSig) =
+        ignore (path, synModuleOrNamespaceSig)
+        None
+
+    /// VisitModuleDecl allows overriding signature module declaration behavior
+    abstract VisitModuleSigDecl:
+        path: SyntaxVisitorPath * defaultTraverse: (SynModuleSigDecl -> 'T option) * synModuleSigDecl: SynModuleSigDecl -> 'T option
+
+    default _.VisitModuleSigDecl(path, defaultTraverse, synModuleSigDecl) =
+        ignore path
+        defaultTraverse synModuleSigDecl
+
+    /// VisitValSig allows overriding SynValSig behavior
+    abstract VisitValSig: path: SyntaxVisitorPath * defaultTraverse: (SynValSig -> 'T option) * valSig: SynValSig -> 'T option
+
+    default _.VisitValSig(path, defaultTraverse, valSig) =
+        ignore path
+        defaultTraverse valSig
+
 /// A range of utility functions to assist with traversing an AST
 module SyntaxTraversal =
     // treat ranges as though they are half-open: [,)
@@ -926,6 +953,101 @@ module SyntaxTraversal =
             attributes
             |> List.map (fun attributes -> dive () attributes.Range (fun () -> visitor.VisitAttributeApplication(origPath, attributes)))
 
+        and traverseSynModuleOrNamespaceSig origPath (SynModuleOrNamespaceSig (decls = synModuleSigDecls; range = range) as mors) =
+            match visitor.VisitModuleOrNamespaceSig(origPath, mors) with
+            | Some x -> Some x
+            | None ->
+                let path = SyntaxNode.SynModuleOrNamespaceSig mors :: origPath
+
+                synModuleSigDecls
+                |> List.map (fun x -> dive x x.Range (traverseSynModuleSigDecl path))
+                |> pick range mors
+
+        and traverseSynModuleSigDecl origPath (decl: SynModuleSigDecl) =
+            let pick = pick decl.Range
+
+            let defaultTraverse m =
+                let path = SyntaxNode.SynModuleSigDecl m :: origPath
+
+                match m with
+                | SynModuleSigDecl.ModuleAbbrev (_ident, _longIdent, _range) -> None
+                | SynModuleSigDecl.NestedModule (moduleDecls = synModuleDecls; moduleInfo = SynComponentInfo (attributes = attributes)) ->
+                    synModuleDecls
+                    |> List.map (fun x -> dive x x.Range (traverseSynModuleSigDecl path))
+                    |> List.append (attributeApplicationDives path attributes)
+                    |> pick decl
+                | SynModuleSigDecl.Val (synValSig, range) -> [ dive synValSig range (traverseSynValSig path) ] |> pick decl
+                | SynModuleSigDecl.Types (types = types; range = range) ->
+                    types
+                    |> List.map (fun t -> dive t range (traverseSynTypeDefnSig path))
+                    |> pick decl
+                | SynModuleSigDecl.Exception (_synExceptionDefn, _range) -> None
+                | SynModuleSigDecl.Open (_target, _range) -> None
+                | SynModuleSigDecl.HashDirective (parsedHashDirective, range) ->
+                    visitor.VisitHashDirective(path, parsedHashDirective, range)
+                | SynModuleSigDecl.NamespaceFragment synModuleOrNamespaceSig -> traverseSynModuleOrNamespaceSig path synModuleOrNamespaceSig
+
+            visitor.VisitModuleSigDecl(origPath, defaultTraverse, decl)
+
+        and traverseSynValSig origPath (valSig: SynValSig) =
+            let defaultTraverse (SynValSig (synType = t; attributes = attributes; synExpr = expr; range = m)) =
+                let path = SyntaxNode.SynValSig valSig :: origPath
+
+                [
+                    yield! attributeApplicationDives path attributes
+                    yield dive t t.Range (traverseSynType path)
+                    match expr with
+                    | Some expr -> yield dive expr expr.Range (traverseSynExpr path)
+                    | None -> ()
+                ]
+                |> pick m valSig
+
+            visitor.VisitValSig(origPath, defaultTraverse, valSig)
+
+        and traverseSynTypeDefnSig origPath (SynTypeDefnSig (synComponentInfo, typeRepr, members, tRange, _) as tydef) =
+            let path = SyntaxNode.SynTypeDefnSig tydef :: origPath
+
+            match visitor.VisitComponentInfo(origPath, synComponentInfo) with
+            | Some x -> Some x
+            | None ->
+                match synComponentInfo with
+                | SynComponentInfo (attributes = attributes) ->
+                    [
+                        yield! attributeApplicationDives path attributes
+
+                        match typeRepr with
+                        | SynTypeDefnSigRepr.Exception _ ->
+                            // This node is generated in CheckExpressions.fs, not in the AST.
+                            // But note exception declarations are missing from this tree walk.
+                            ()
+                        | SynTypeDefnSigRepr.ObjectModel (memberSigs = memberSigs) ->
+                            yield! memberSigs |> List.map (fun ms -> dive ms ms.Range (traverseSynMemberSig path))
+                        | SynTypeDefnSigRepr.Simple (synTypeDefnSimpleRepr, _range) ->
+                            match synTypeDefnSimpleRepr with
+                            | SynTypeDefnSimpleRepr.Record (_synAccessOption, fields, m) ->
+                                yield dive () typeRepr.Range (fun () -> traverseRecordDefn path fields m)
+                            | SynTypeDefnSimpleRepr.Union (_synAccessOption, cases, m) ->
+                                yield dive () typeRepr.Range (fun () -> traverseUnionDefn path cases m)
+                            | SynTypeDefnSimpleRepr.Enum (cases, m) ->
+                                yield dive () typeRepr.Range (fun () -> traverseEnumDefn path cases m)
+                            | SynTypeDefnSimpleRepr.TypeAbbrev (_, synType, m) ->
+                                yield dive typeRepr typeRepr.Range (fun _ -> visitor.VisitTypeAbbrev(path, synType, m))
+                            | _ -> ()
+                        yield! members |> List.map (fun ms -> dive ms ms.Range (traverseSynMemberSig path))
+                    ]
+                    |> pick tRange tydef
+
+        and traverseSynMemberSig path (m: SynMemberSig) =
+            let path = SyntaxNode.SynMemberSig m :: path
+
+            match m with
+            | SynMemberSig.Member (memberSig = memberSig) -> traverseSynValSig path memberSig
+            | SynMemberSig.Interface (interfaceType = synType) -> traverseSynType path synType
+            | SynMemberSig.Inherit (inheritedType = synType) -> traverseSynType path synType
+            | SynMemberSig.ValField(field = SynField (attributes = attributes)) ->
+                attributeApplicationDives path attributes |> pick m.Range attributes
+            | SynMemberSig.NestedType (nestedType = nestedType) -> traverseSynTypeDefnSig path nestedType
+
         match parseTree with
         | ParsedInput.ImplFile file ->
             let l = file.Contents
@@ -941,4 +1063,17 @@ module SyntaxTraversal =
             l
             |> List.map (fun x -> dive x x.Range (traverseSynModuleOrNamespace []))
             |> pick fileRange l
-        | ParsedInput.SigFile _sigFile -> None
+        | ParsedInput.SigFile sigFile ->
+            let l = sigFile.Contents
+
+            let fileRange =
+#if DEBUG
+                match l with
+                | [] -> range0
+                | _ -> l |> List.map (fun x -> x.Range) |> List.reduce unionRanges
+#else
+                range0 // only used for asserting, does not matter in non-debug
+#endif
+            l
+            |> List.map (fun x -> dive x x.Range (traverseSynModuleOrNamespaceSig []))
+            |> pick fileRange l
diff --git a/src/Compiler/Service/ServiceParseTreeWalk.fsi b/src/Compiler/Service/ServiceParseTreeWalk.fsi
index d073ca1e73c..0a17dd468ec 100644
--- a/src/Compiler/Service/ServiceParseTreeWalk.fsi
+++ b/src/Compiler/Service/ServiceParseTreeWalk.fsi
@@ -17,6 +17,11 @@ type SyntaxNode =
     | SynMemberDefn of SynMemberDefn
     | SynMatchClause of SynMatchClause
     | SynBinding of SynBinding
+    | SynModuleOrNamespaceSig of SynModuleOrNamespaceSig
+    | SynModuleSigDecl of SynModuleSigDecl
+    | SynValSig of SynValSig
+    | SynTypeDefnSig of SynTypeDefnSig
+    | SynMemberSig of SynMemberSig
 
 type SyntaxVisitorPath = SyntaxNode list
 
@@ -151,6 +156,24 @@ type SyntaxVisitorBase<'T> =
     abstract VisitAttributeApplication: path: SyntaxVisitorPath * attributes: SynAttributeList -> 'T option
     default VisitAttributeApplication: path: SyntaxVisitorPath * attributes: SynAttributeList -> 'T option
 
+    abstract VisitModuleOrNamespaceSig:
+        path: SyntaxVisitorPath * synModuleOrNamespaceSig: SynModuleOrNamespaceSig -> 'T option
+    default VisitModuleOrNamespaceSig:
+        path: SyntaxVisitorPath * synModuleOrNamespaceSig: SynModuleOrNamespaceSig -> 'T option
+
+    abstract VisitModuleSigDecl:
+        path: SyntaxVisitorPath * defaultTraverse: (SynModuleSigDecl -> 'T option) * synModuleSigDecl: SynModuleSigDecl ->
+            'T option
+    default VisitModuleSigDecl:
+        path: SyntaxVisitorPath * defaultTraverse: (SynModuleSigDecl -> 'T option) * synModuleSigDecl: SynModuleSigDecl ->
+            'T option
+
+    abstract VisitValSig:
+        path: SyntaxVisitorPath * defaultTraverse: (SynValSig -> 'T option) * valSig: SynValSig -> 'T option
+
+    default VisitValSig:
+        path: SyntaxVisitorPath * defaultTraverse: (SynValSig -> 'T option) * valSig: SynValSig -> 'T option
+
 module public SyntaxTraversal =
 
     val internal rangeContainsPosLeftEdgeInclusive: m1: range -> p: pos -> bool
diff --git a/tests/FSharp.Compiler.Service.Tests/FSharp.Compiler.Service.SurfaceArea.netstandard20.debug.bsl b/tests/FSharp.Compiler.Service.Tests/FSharp.Compiler.Service.SurfaceArea.netstandard20.debug.bsl
index dd4fec52d42..9f3b2c381aa 100644
--- a/tests/FSharp.Compiler.Service.Tests/FSharp.Compiler.Service.SurfaceArea.netstandard20.debug.bsl
+++ b/tests/FSharp.Compiler.Service.Tests/FSharp.Compiler.Service.SurfaceArea.netstandard20.debug.bsl
@@ -9238,61 +9238,96 @@ FSharp.Compiler.Syntax.SyntaxNode+SynMatchClause: FSharp.Compiler.Syntax.SynMatc
 FSharp.Compiler.Syntax.SyntaxNode+SynMatchClause: FSharp.Compiler.Syntax.SynMatchClause get_Item()
 FSharp.Compiler.Syntax.SyntaxNode+SynMemberDefn: FSharp.Compiler.Syntax.SynMemberDefn Item
 FSharp.Compiler.Syntax.SyntaxNode+SynMemberDefn: FSharp.Compiler.Syntax.SynMemberDefn get_Item()
+FSharp.Compiler.Syntax.SyntaxNode+SynMemberSig: FSharp.Compiler.Syntax.SynMemberSig Item
+FSharp.Compiler.Syntax.SyntaxNode+SynMemberSig: FSharp.Compiler.Syntax.SynMemberSig get_Item()
 FSharp.Compiler.Syntax.SyntaxNode+SynModule: FSharp.Compiler.Syntax.SynModuleDecl Item
 FSharp.Compiler.Syntax.SyntaxNode+SynModule: FSharp.Compiler.Syntax.SynModuleDecl get_Item()
 FSharp.Compiler.Syntax.SyntaxNode+SynModuleOrNamespace: FSharp.Compiler.Syntax.SynModuleOrNamespace Item
 FSharp.Compiler.Syntax.SyntaxNode+SynModuleOrNamespace: FSharp.Compiler.Syntax.SynModuleOrNamespace get_Item()
+FSharp.Compiler.Syntax.SyntaxNode+SynModuleOrNamespaceSig: FSharp.Compiler.Syntax.SynModuleOrNamespaceSig Item
+FSharp.Compiler.Syntax.SyntaxNode+SynModuleOrNamespaceSig: FSharp.Compiler.Syntax.SynModuleOrNamespaceSig get_Item()
+FSharp.Compiler.Syntax.SyntaxNode+SynModuleSigDecl: FSharp.Compiler.Syntax.SynModuleSigDecl Item
+FSharp.Compiler.Syntax.SyntaxNode+SynModuleSigDecl: FSharp.Compiler.Syntax.SynModuleSigDecl get_Item()
 FSharp.Compiler.Syntax.SyntaxNode+SynPat: FSharp.Compiler.Syntax.SynPat Item
 FSharp.Compiler.Syntax.SyntaxNode+SynPat: FSharp.Compiler.Syntax.SynPat get_Item()
 FSharp.Compiler.Syntax.SyntaxNode+SynType: FSharp.Compiler.Syntax.SynType Item
 FSharp.Compiler.Syntax.SyntaxNode+SynType: FSharp.Compiler.Syntax.SynType get_Item()
 FSharp.Compiler.Syntax.SyntaxNode+SynTypeDefn: FSharp.Compiler.Syntax.SynTypeDefn Item
 FSharp.Compiler.Syntax.SyntaxNode+SynTypeDefn: FSharp.Compiler.Syntax.SynTypeDefn get_Item()
+FSharp.Compiler.Syntax.SyntaxNode+SynTypeDefnSig: FSharp.Compiler.Syntax.SynTypeDefnSig Item
+FSharp.Compiler.Syntax.SyntaxNode+SynTypeDefnSig: FSharp.Compiler.Syntax.SynTypeDefnSig get_Item()
+FSharp.Compiler.Syntax.SyntaxNode+SynValSig: FSharp.Compiler.Syntax.SynValSig Item
+FSharp.Compiler.Syntax.SyntaxNode+SynValSig: FSharp.Compiler.Syntax.SynValSig get_Item()
 FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynBinding
 FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynExpr
 FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynMatchClause
 FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynMemberDefn
+FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynMemberSig
 FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynModule
 FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynModuleOrNamespace
+FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynModuleOrNamespaceSig
+FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynModuleSigDecl
 FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynPat
 FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynType
 FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynTypeDefn
+FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynTypeDefnSig
+FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynValSig
 FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynBinding
 FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynExpr
 FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynMatchClause
 FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynMemberDefn
+FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynMemberSig
 FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynModule
 FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynModuleOrNamespace
+FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynModuleOrNamespaceSig
+FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynModuleSigDecl
 FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynPat
 FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynType
 FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynTypeDefn
+FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynTypeDefnSig
+FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynValSig
 FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynBinding()
 FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynExpr()
 FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynMatchClause()
 FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynMemberDefn()
+FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynMemberSig()
 FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynModule()
 FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynModuleOrNamespace()
+FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynModuleOrNamespaceSig()
+FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynModuleSigDecl()
 FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynPat()
 FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynType()
 FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynTypeDefn()
+FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynTypeDefnSig()
+FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynValSig()
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynBinding(FSharp.Compiler.Syntax.SynBinding)
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynExpr(FSharp.Compiler.Syntax.SynExpr)
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynMatchClause(FSharp.Compiler.Syntax.SynMatchClause)
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynMemberDefn(FSharp.Compiler.Syntax.SynMemberDefn)
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynMemberSig(FSharp.Compiler.Syntax.SynMemberSig)
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynModule(FSharp.Compiler.Syntax.SynModuleDecl)
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynModuleOrNamespace(FSharp.Compiler.Syntax.SynModuleOrNamespace)
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynModuleOrNamespaceSig(FSharp.Compiler.Syntax.SynModuleOrNamespaceSig)
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynModuleSigDecl(FSharp.Compiler.Syntax.SynModuleSigDecl)
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynPat(FSharp.Compiler.Syntax.SynPat)
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynType(FSharp.Compiler.Syntax.SynType)
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynTypeDefn(FSharp.Compiler.Syntax.SynTypeDefn)
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynTypeDefnSig(FSharp.Compiler.Syntax.SynTypeDefnSig)
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynValSig(FSharp.Compiler.Syntax.SynValSig)
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynBinding
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynExpr
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynMatchClause
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynMemberDefn
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynMemberSig
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynModule
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynModuleOrNamespace
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynModuleOrNamespaceSig
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynModuleSigDecl
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynPat
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynType
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynTypeDefn
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynTypeDefnSig
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynValSig
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+Tags
 FSharp.Compiler.Syntax.SyntaxNode: Int32 Tag
 FSharp.Compiler.Syntax.SyntaxNode: Int32 get_Tag()
@@ -9311,6 +9346,8 @@ FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOptio
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitMatchClause(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], Microsoft.FSharp.Core.FSharpFunc`2[FSharp.Compiler.Syntax.SynMatchClause,Microsoft.FSharp.Core.FSharpOption`1[T]], FSharp.Compiler.Syntax.SynMatchClause)
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitModuleDecl(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], Microsoft.FSharp.Core.FSharpFunc`2[FSharp.Compiler.Syntax.SynModuleDecl,Microsoft.FSharp.Core.FSharpOption`1[T]], FSharp.Compiler.Syntax.SynModuleDecl)
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitModuleOrNamespace(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], FSharp.Compiler.Syntax.SynModuleOrNamespace)
+FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitModuleOrNamespaceSig(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], FSharp.Compiler.Syntax.SynModuleOrNamespaceSig)
+FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitModuleSigDecl(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], Microsoft.FSharp.Core.FSharpFunc`2[FSharp.Compiler.Syntax.SynModuleSigDecl,Microsoft.FSharp.Core.FSharpOption`1[T]], FSharp.Compiler.Syntax.SynModuleSigDecl)
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitPat(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], Microsoft.FSharp.Core.FSharpFunc`2[FSharp.Compiler.Syntax.SynPat,Microsoft.FSharp.Core.FSharpOption`1[T]], FSharp.Compiler.Syntax.SynPat)
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitRecordDefn(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SynField], FSharp.Compiler.Text.Range)
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitRecordField(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.Syntax.SynExpr], Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.Syntax.SynLongIdent])
@@ -9318,6 +9355,7 @@ FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOptio
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitType(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], Microsoft.FSharp.Core.FSharpFunc`2[FSharp.Compiler.Syntax.SynType,Microsoft.FSharp.Core.FSharpOption`1[T]], FSharp.Compiler.Syntax.SynType)
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitTypeAbbrev(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], FSharp.Compiler.Syntax.SynType, FSharp.Compiler.Text.Range)
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitUnionDefn(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SynUnionCase], FSharp.Compiler.Text.Range)
+FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitValSig(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], Microsoft.FSharp.Core.FSharpFunc`2[FSharp.Compiler.Syntax.SynValSig,Microsoft.FSharp.Core.FSharpOption`1[T]], FSharp.Compiler.Syntax.SynValSig)
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Void .ctor()
 FSharp.Compiler.Syntax.TyparStaticReq+Tags: Int32 HeadType
 FSharp.Compiler.Syntax.TyparStaticReq+Tags: Int32 None
diff --git a/tests/FSharp.Compiler.Service.Tests/FSharp.Compiler.Service.SurfaceArea.netstandard20.release.bsl b/tests/FSharp.Compiler.Service.Tests/FSharp.Compiler.Service.SurfaceArea.netstandard20.release.bsl
index dd4fec52d42..9f3b2c381aa 100644
--- a/tests/FSharp.Compiler.Service.Tests/FSharp.Compiler.Service.SurfaceArea.netstandard20.release.bsl
+++ b/tests/FSharp.Compiler.Service.Tests/FSharp.Compiler.Service.SurfaceArea.netstandard20.release.bsl
@@ -9238,61 +9238,96 @@ FSharp.Compiler.Syntax.SyntaxNode+SynMatchClause: FSharp.Compiler.Syntax.SynMatc
 FSharp.Compiler.Syntax.SyntaxNode+SynMatchClause: FSharp.Compiler.Syntax.SynMatchClause get_Item()
 FSharp.Compiler.Syntax.SyntaxNode+SynMemberDefn: FSharp.Compiler.Syntax.SynMemberDefn Item
 FSharp.Compiler.Syntax.SyntaxNode+SynMemberDefn: FSharp.Compiler.Syntax.SynMemberDefn get_Item()
+FSharp.Compiler.Syntax.SyntaxNode+SynMemberSig: FSharp.Compiler.Syntax.SynMemberSig Item
+FSharp.Compiler.Syntax.SyntaxNode+SynMemberSig: FSharp.Compiler.Syntax.SynMemberSig get_Item()
 FSharp.Compiler.Syntax.SyntaxNode+SynModule: FSharp.Compiler.Syntax.SynModuleDecl Item
 FSharp.Compiler.Syntax.SyntaxNode+SynModule: FSharp.Compiler.Syntax.SynModuleDecl get_Item()
 FSharp.Compiler.Syntax.SyntaxNode+SynModuleOrNamespace: FSharp.Compiler.Syntax.SynModuleOrNamespace Item
 FSharp.Compiler.Syntax.SyntaxNode+SynModuleOrNamespace: FSharp.Compiler.Syntax.SynModuleOrNamespace get_Item()
+FSharp.Compiler.Syntax.SyntaxNode+SynModuleOrNamespaceSig: FSharp.Compiler.Syntax.SynModuleOrNamespaceSig Item
+FSharp.Compiler.Syntax.SyntaxNode+SynModuleOrNamespaceSig: FSharp.Compiler.Syntax.SynModuleOrNamespaceSig get_Item()
+FSharp.Compiler.Syntax.SyntaxNode+SynModuleSigDecl: FSharp.Compiler.Syntax.SynModuleSigDecl Item
+FSharp.Compiler.Syntax.SyntaxNode+SynModuleSigDecl: FSharp.Compiler.Syntax.SynModuleSigDecl get_Item()
 FSharp.Compiler.Syntax.SyntaxNode+SynPat: FSharp.Compiler.Syntax.SynPat Item
 FSharp.Compiler.Syntax.SyntaxNode+SynPat: FSharp.Compiler.Syntax.SynPat get_Item()
 FSharp.Compiler.Syntax.SyntaxNode+SynType: FSharp.Compiler.Syntax.SynType Item
 FSharp.Compiler.Syntax.SyntaxNode+SynType: FSharp.Compiler.Syntax.SynType get_Item()
 FSharp.Compiler.Syntax.SyntaxNode+SynTypeDefn: FSharp.Compiler.Syntax.SynTypeDefn Item
 FSharp.Compiler.Syntax.SyntaxNode+SynTypeDefn: FSharp.Compiler.Syntax.SynTypeDefn get_Item()
+FSharp.Compiler.Syntax.SyntaxNode+SynTypeDefnSig: FSharp.Compiler.Syntax.SynTypeDefnSig Item
+FSharp.Compiler.Syntax.SyntaxNode+SynTypeDefnSig: FSharp.Compiler.Syntax.SynTypeDefnSig get_Item()
+FSharp.Compiler.Syntax.SyntaxNode+SynValSig: FSharp.Compiler.Syntax.SynValSig Item
+FSharp.Compiler.Syntax.SyntaxNode+SynValSig: FSharp.Compiler.Syntax.SynValSig get_Item()
 FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynBinding
 FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynExpr
 FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynMatchClause
 FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynMemberDefn
+FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynMemberSig
 FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynModule
 FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynModuleOrNamespace
+FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynModuleOrNamespaceSig
+FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynModuleSigDecl
 FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynPat
 FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynType
 FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynTypeDefn
+FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynTypeDefnSig
+FSharp.Compiler.Syntax.SyntaxNode+Tags: Int32 SynValSig
 FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynBinding
 FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynExpr
 FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynMatchClause
 FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynMemberDefn
+FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynMemberSig
 FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynModule
 FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynModuleOrNamespace
+FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynModuleOrNamespaceSig
+FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynModuleSigDecl
 FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynPat
 FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynType
 FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynTypeDefn
+FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynTypeDefnSig
+FSharp.Compiler.Syntax.SyntaxNode: Boolean IsSynValSig
 FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynBinding()
 FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynExpr()
 FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynMatchClause()
 FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynMemberDefn()
+FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynMemberSig()
 FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynModule()
 FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynModuleOrNamespace()
+FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynModuleOrNamespaceSig()
+FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynModuleSigDecl()
 FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynPat()
 FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynType()
 FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynTypeDefn()
+FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynTypeDefnSig()
+FSharp.Compiler.Syntax.SyntaxNode: Boolean get_IsSynValSig()
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynBinding(FSharp.Compiler.Syntax.SynBinding)
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynExpr(FSharp.Compiler.Syntax.SynExpr)
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynMatchClause(FSharp.Compiler.Syntax.SynMatchClause)
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynMemberDefn(FSharp.Compiler.Syntax.SynMemberDefn)
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynMemberSig(FSharp.Compiler.Syntax.SynMemberSig)
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynModule(FSharp.Compiler.Syntax.SynModuleDecl)
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynModuleOrNamespace(FSharp.Compiler.Syntax.SynModuleOrNamespace)
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynModuleOrNamespaceSig(FSharp.Compiler.Syntax.SynModuleOrNamespaceSig)
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynModuleSigDecl(FSharp.Compiler.Syntax.SynModuleSigDecl)
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynPat(FSharp.Compiler.Syntax.SynPat)
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynType(FSharp.Compiler.Syntax.SynType)
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynTypeDefn(FSharp.Compiler.Syntax.SynTypeDefn)
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynTypeDefnSig(FSharp.Compiler.Syntax.SynTypeDefnSig)
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode NewSynValSig(FSharp.Compiler.Syntax.SynValSig)
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynBinding
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynExpr
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynMatchClause
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynMemberDefn
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynMemberSig
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynModule
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynModuleOrNamespace
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynModuleOrNamespaceSig
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynModuleSigDecl
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynPat
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynType
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynTypeDefn
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynTypeDefnSig
+FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+SynValSig
 FSharp.Compiler.Syntax.SyntaxNode: FSharp.Compiler.Syntax.SyntaxNode+Tags
 FSharp.Compiler.Syntax.SyntaxNode: Int32 Tag
 FSharp.Compiler.Syntax.SyntaxNode: Int32 get_Tag()
@@ -9311,6 +9346,8 @@ FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOptio
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitMatchClause(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], Microsoft.FSharp.Core.FSharpFunc`2[FSharp.Compiler.Syntax.SynMatchClause,Microsoft.FSharp.Core.FSharpOption`1[T]], FSharp.Compiler.Syntax.SynMatchClause)
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitModuleDecl(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], Microsoft.FSharp.Core.FSharpFunc`2[FSharp.Compiler.Syntax.SynModuleDecl,Microsoft.FSharp.Core.FSharpOption`1[T]], FSharp.Compiler.Syntax.SynModuleDecl)
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitModuleOrNamespace(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], FSharp.Compiler.Syntax.SynModuleOrNamespace)
+FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitModuleOrNamespaceSig(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], FSharp.Compiler.Syntax.SynModuleOrNamespaceSig)
+FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitModuleSigDecl(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], Microsoft.FSharp.Core.FSharpFunc`2[FSharp.Compiler.Syntax.SynModuleSigDecl,Microsoft.FSharp.Core.FSharpOption`1[T]], FSharp.Compiler.Syntax.SynModuleSigDecl)
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitPat(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], Microsoft.FSharp.Core.FSharpFunc`2[FSharp.Compiler.Syntax.SynPat,Microsoft.FSharp.Core.FSharpOption`1[T]], FSharp.Compiler.Syntax.SynPat)
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitRecordDefn(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SynField], FSharp.Compiler.Text.Range)
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitRecordField(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.Syntax.SynExpr], Microsoft.FSharp.Core.FSharpOption`1[FSharp.Compiler.Syntax.SynLongIdent])
@@ -9318,6 +9355,7 @@ FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOptio
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitType(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], Microsoft.FSharp.Core.FSharpFunc`2[FSharp.Compiler.Syntax.SynType,Microsoft.FSharp.Core.FSharpOption`1[T]], FSharp.Compiler.Syntax.SynType)
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitTypeAbbrev(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], FSharp.Compiler.Syntax.SynType, FSharp.Compiler.Text.Range)
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitUnionDefn(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SynUnionCase], FSharp.Compiler.Text.Range)
+FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Microsoft.FSharp.Core.FSharpOption`1[T] VisitValSig(Microsoft.FSharp.Collections.FSharpList`1[FSharp.Compiler.Syntax.SyntaxNode], Microsoft.FSharp.Core.FSharpFunc`2[FSharp.Compiler.Syntax.SynValSig,Microsoft.FSharp.Core.FSharpOption`1[T]], FSharp.Compiler.Syntax.SynValSig)
 FSharp.Compiler.Syntax.SyntaxVisitorBase`1[T]: Void .ctor()
 FSharp.Compiler.Syntax.TyparStaticReq+Tags: Int32 HeadType
 FSharp.Compiler.Syntax.TyparStaticReq+Tags: Int32 None
diff --git a/tests/FSharp.Compiler.UnitTests/TreeVisitorTests.fs b/tests/FSharp.Compiler.UnitTests/TreeVisitorTests.fs
index 60ebf8c68d4..a450e3374d2 100644
--- a/tests/FSharp.Compiler.UnitTests/TreeVisitorTests.fs
+++ b/tests/FSharp.Compiler.UnitTests/TreeVisitorTests.fs
@@ -75,3 +75,95 @@ let ``Visit recursive let binding`` () =
     match SyntaxTraversal.Traverse(pos0, parseTree, visitor) with
     | Some [ SynBinding(valData = SynValData(valInfo = SynValInfo(curriedArgInfos = [ [ SynArgInfo(ident = Some id) ] ]))) ] when id.idText = "n" -> ()
     | _ -> failwith "Did not visit recursive let binding"
+
+[<Fact>]
+let ``Visit ValSig`` () =
+    let visitor =
+        { new SyntaxVisitorBase<_>() with
+            member x.VisitValSig(path, defaultTraverse, SynValSig(ident = SynIdent(ident = valIdent))) =
+                Some valIdent.idText
+        }
+
+    let source = """
+module X
+
+val y: int -> int
+"""
+
+    let parseTree = parseSourceCode("C:\\test.fsi", source)
+
+    match SyntaxTraversal.Traverse(pos0, parseTree, visitor) with
+    | Some "y" -> ()
+    | _ -> failwith "Did not visit SynValSig"
+
+[<Fact>]
+let ``Visit nested ValSig`` () =
+    let visitor =
+        { new SyntaxVisitorBase<_>() with
+            member x.VisitValSig(path, defaultTraverse, SynValSig(ident = SynIdent(ident = valIdent))) =
+                Some valIdent.idText
+        }
+
+    let source = """
+module X
+
+module Y =
+    val z: int -> int
+"""
+
+    let parseTree = parseSourceCode("C:\\test.fsi", source)
+
+    match SyntaxTraversal.Traverse(pos0, parseTree, visitor) with
+    | Some "z" -> ()
+    | _ -> failwith "Did not visit SynValSig"
+
+[<Fact>]
+let ``Visit Record in SynTypeDefnSig`` () =
+    let visitor =
+        { new SyntaxVisitorBase<_>() with
+            member x.VisitRecordDefn(path, fields, range) =
+                fields
+                |> List.choose (fun (SynField(idOpt = idOpt)) -> idOpt |> Option.map (fun ident -> ident.idText))
+                |> String.concat ","
+                |> Some
+        }
+
+    let source = """
+module X
+
+type Y =
+    {
+        A: int
+        B: char
+        C: string
+    }
+"""
+
+    let parseTree = parseSourceCode("C:\\test.fsi", source)
+
+    match SyntaxTraversal.Traverse(pos0, parseTree, visitor) with
+    | Some "A,B,C" -> ()
+    | _ -> failwith "Did not visit SynTypeDefnSimpleRepr.Record in SynTypeDefnSig"
+
+[<Fact>]
+let ``Visit SynValSig in SynMemberSig`` () =
+    let visitor =
+        { new SyntaxVisitorBase<_>() with
+            member x.VisitValSig(path, defaultTraverse, SynValSig(ident = SynIdent(ident = valIdent))) =
+                Some valIdent.idText
+        }
+
+    let source = """
+module Lib
+
+type Meh =
+    new: unit -> Meh
+    member Foo: y: int -> int
+"""
+
+    let parseTree = parseSourceCode("C:\\test.fsi", source)
+    let pos = mkPos 6 4
+
+    match SyntaxTraversal.Traverse(pos, parseTree, visitor) with
+    | Some "Foo" -> ()
+    | _ -> failwith "Did not visit SynValSig in SynMemberSig.Member"