diff --git a/src/Java.Interop.Tools.Cecil/Java.Interop.Tools.Cecil/DirectoryAssemblyResolver.cs b/src/Java.Interop.Tools.Cecil/Java.Interop.Tools.Cecil/DirectoryAssemblyResolver.cs
index 7068c4112..d2a41d9d0 100644
--- a/src/Java.Interop.Tools.Cecil/Java.Interop.Tools.Cecil/DirectoryAssemblyResolver.cs
+++ b/src/Java.Interop.Tools.Cecil/Java.Interop.Tools.Cecil/DirectoryAssemblyResolver.cs
@@ -64,7 +64,12 @@ public class DirectoryAssemblyResolver : IAssemblyResolver {
 		bool loadDebugSymbols;
 		Action<string, object[]> logWarnings;
 
-		public DirectoryAssemblyResolver (Action<string, object[]> logWarnings, bool loadDebugSymbols)
+		ReaderParameters                        loadReaderParameters;
+
+		static  readonly    ReaderParameters    DefaultLoadReaderParameters = new ReaderParameters {
+		};
+
+		public DirectoryAssemblyResolver (Action<string, object[]> logWarnings, bool loadDebugSymbols, ReaderParameters loadReaderParameters = null)
 		{
 			if (logWarnings == null)
 				throw new ArgumentNullException (nameof (logWarnings));
@@ -72,6 +77,7 @@ public DirectoryAssemblyResolver (Action<string, object[]> logWarnings, bool loa
 			this.loadDebugSymbols = loadDebugSymbols;
 			this.logWarnings = logWarnings;
 			SearchDirectories = new List<string> ();
+			this.loadReaderParameters = loadReaderParameters ?? DefaultLoadReaderParameters;
 		}
 
 		public void Dispose ()
@@ -82,8 +88,15 @@ public void Dispose ()
 
 		protected virtual void Dispose (bool disposing)
 		{
+			if (!disposing || cache == null)
+				return;
+			foreach (var e in cache) {
+				e.Value.Dispose ();
+			}
+			cache = null;
 		}
 
+		[Obsolete ("Should not be used; was required with previous Cecil versions.")]
 		public IDictionary ToResolverCache ()
 		{
 			var resolver_cache = new Hashtable ();
@@ -114,9 +127,21 @@ public virtual AssemblyDefinition Load (string fileName)
 
 		protected virtual AssemblyDefinition ReadAssembly (string file)
 		{
+			bool haveDebugSymbols = loadDebugSymbols &&
+				(File.Exists (file + ".mdb") ||
+				 File.Exists (Path.ChangeExtension (file, ".pdb")));
 			var reader_parameters = new ReaderParameters () {
-				AssemblyResolver  = this,
-				ReadSymbols       = loadDebugSymbols && (File.Exists(file + ".mdb") || File.Exists(Path.ChangeExtension(file, ".pdb"))),
+				ApplyWindowsRuntimeProjections  = loadReaderParameters.ApplyWindowsRuntimeProjections,
+				AssemblyResolver                = this,
+				MetadataImporterProvider        = loadReaderParameters.MetadataImporterProvider,
+				InMemory                        = loadReaderParameters.InMemory,
+				MetadataResolver                = loadReaderParameters.MetadataResolver,
+				ReadingMode                     = loadReaderParameters.ReadingMode,
+				ReadSymbols                     = haveDebugSymbols,
+				ReadWrite                       = loadReaderParameters.ReadWrite,
+				ReflectionImporterProvider      = loadReaderParameters.ReflectionImporterProvider,
+				SymbolReaderProvider            = loadReaderParameters.SymbolReaderProvider,
+				SymbolStream                    = loadReaderParameters.SymbolStream,
 			};
 			try {
 				return AssemblyDefinition.ReadAssembly (file, reader_parameters);
diff --git a/src/Java.Interop.Tools.JavaCallableWrappers/Java.Interop.Tools.JavaCallableWrappers/TypeNameMapGenerator.cs b/src/Java.Interop.Tools.JavaCallableWrappers/Java.Interop.Tools.JavaCallableWrappers/TypeNameMapGenerator.cs
index 188aba9f5..a39775135 100644
--- a/src/Java.Interop.Tools.JavaCallableWrappers/Java.Interop.Tools.JavaCallableWrappers/TypeNameMapGenerator.cs
+++ b/src/Java.Interop.Tools.JavaCallableWrappers/Java.Interop.Tools.JavaCallableWrappers/TypeNameMapGenerator.cs
@@ -68,13 +68,15 @@ public TypeNameMapGenerator (IEnumerable<string> assemblies, Action<string, obje
 
 			Log             = logMessage;
 			var Assemblies  = assemblies.ToList ();
-			var resolver    = new DirectoryAssemblyResolver (Log, loadDebugSymbols: true);
+			var rp          = new ReaderParameters (ReadingMode.Immediate);
 
-			foreach (var assembly in Assemblies) {
-				resolver.Load (Path.GetFullPath (assembly));
-			}
+			using (var resolver = new DirectoryAssemblyResolver (Log, loadDebugSymbols: true, loadReaderParameters: rp)) {
+				foreach (var assembly in Assemblies) {
+					resolver.Load (Path.GetFullPath (assembly));
+				}
 
-			Types       = JavaTypeScanner.GetJavaTypes (Assemblies, resolver, logMessage);
+				Types       = JavaTypeScanner.GetJavaTypes (Assemblies, resolver, logMessage);
+			}
 		}
 
 		public TypeNameMapGenerator (IEnumerable<TypeDefinition> types, Action<string, object[]> logMessage)
diff --git a/tools/generator/CodeGenerator.cs b/tools/generator/CodeGenerator.cs
index 320863cf6..2a9760a29 100644
--- a/tools/generator/CodeGenerator.cs
+++ b/tools/generator/CodeGenerator.cs
@@ -209,6 +209,13 @@ public static void Run (CodeGeneratorOptions options)
 			if (options == null)
 				throw new ArgumentNullException ("options");
 
+			using (var resolver = new DirectoryAssemblyResolver (Console.WriteLine, loadDebugSymbols: false)) {
+				Run (options, resolver);
+			}
+		}
+
+		static void Run (CodeGeneratorOptions options, DirectoryAssemblyResolver resolver)
+		{
 			string assemblyQN       = options.AssemblyQualifiedName;
 			string api_level        = options.ApiLevel;
 			int product_version     = options.ProductVersion;
@@ -239,7 +246,6 @@ public static void Run (CodeGeneratorOptions options)
 
 			// Load reference libraries
 
-			var resolver = new DirectoryAssemblyResolver (Console.WriteLine, loadDebugSymbols: false);
 			foreach (var lib in options.LibraryPaths) {
 				resolver.SearchDirectories.Add (lib);
 			}
diff --git a/tools/jcw-gen/App.cs b/tools/jcw-gen/App.cs
index 1f263c698..8de3ac526 100644
--- a/tools/jcw-gen/App.cs
+++ b/tools/jcw-gen/App.cs
@@ -71,6 +71,9 @@ public static int Main (string [] args)
 				Console.Error.Write ("jcw-gen: {0}", verbosity > 0 ? e.ToString () : e.Message);
 				return 1;
 			}
+			finally {
+				resolver.Dispose ();
+			}
 		}
 
 		static void GenerateJavaCallableWrapper (TypeDefinition type, string outputPath)