diff --git a/.gitignore b/.gitignore
index cbf6773ddd1..607a5695e34 100644
--- a/.gitignore
+++ b/.gitignore
@@ -125,3 +125,4 @@ tests/fsharpqa/testenv/bin/System.ValueTuple.dll
 msbuild.binlog
 /fcs/FSharp.Compiler.Service.netstandard/*.fs
 /fcs/FSharp.Compiler.Service.netstandard/*.fsi
+.idea/
diff --git a/src/fsharp/FSComp.txt b/src/fsharp/FSComp.txt
index 63324554f1c..2e94ac16e04 100644
--- a/src/fsharp/FSComp.txt
+++ b/src/fsharp/FSComp.txt
@@ -1458,3 +1458,4 @@ notAFunctionButMaybeDeclaration,"This value is not a function and cannot be appl
 3245,tcCopyAndUpdateNeedsRecordType,"The input to a copy-and-update expression that creates an anonymous record must be either an anonymous record or a record"
 3300,chkInvalidFunctionParameterType,"The parameter '%s' has an invalid type '%s'. This is not permitted by the rules of Common IL."
 3301,chkInvalidFunctionReturnType,"The function or method has an invalid return type '%s'. This is not permitted by the rules of Common IL."
+3302,parsEqualsMissingInTypeDefinition,"Unexpected symbol '{' in type definition. Did you forget to use the = operator?"
diff --git a/src/fsharp/pars.fsy b/src/fsharp/pars.fsy
index 52bbef6d05a..45962313549 100644
--- a/src/fsharp/pars.fsy
+++ b/src/fsharp/pars.fsy
@@ -1441,8 +1441,10 @@ tyconDefn:
   | typeNameInfo 
      { TypeDefn($1,SynTypeDefnRepr.Simple(SynTypeDefnSimpleRepr.None($1.Range),$1.Range),[],$1.Range) }
 
-  | typeNameInfo EQUALS tyconDefnRhsBlock
-     { let nameRange = rhs parseState 1
+  | typeNameInfo opt_EQUALS tyconDefnRhsBlock
+     {
+       if Option.isNone $2 then raiseParseErrorAt (rhs parseState 1) (FSComp.SR.parsEqualsMissingInTypeDefinition())
+       let nameRange = rhs parseState 1
        let (tcDefRepr:SynTypeDefnRepr),members = $3 nameRange
        let declRange = unionRanges (rhs parseState 1) tcDefRepr.Range
        let mWhole = (declRange, members) ||> unionRangeWithListBy (fun (mem:SynMemberDefn) -> mem.Range)    
@@ -4935,6 +4937,10 @@ deprecated_opt_equals:
   | EQUALS      { deprecatedWithError (FSComp.SR.parsNoEqualShouldFollowNamespace()) (lhs parseState); () } 
   | /* EMPTY */ {  }
 
+opt_EQUALS:
+  | EQUALS      { } 
+  | /* EMPTY */ { }
+
 opt_OBLOCKSEP: 
   | OBLOCKSEP   { }
   | /* EMPTY */ { }