diff --git a/ICSharpCode.Decompiler/Ast/Transforms/IntroduceUsingDeclarations.cs b/ICSharpCode.Decompiler/Ast/Transforms/IntroduceUsingDeclarations.cs
index 3fbbef73c..ed2fa5b1c 100644
--- a/ICSharpCode.Decompiler/Ast/Transforms/IntroduceUsingDeclarations.cs
+++ b/ICSharpCode.Decompiler/Ast/Transforms/IntroduceUsingDeclarations.cs
@@ -44,6 +44,9 @@ namespace ICSharpCode.Decompiler.Ast.Transforms
 				compilationUnit.InsertChildAfter(null, new UsingDeclaration { Import = nsType }, CompilationUnit.MemberRole);
 			}
 			
+			if (!context.Settings.FullyQualifyAmbiguousTypeNames)
+				return;
+			
 			FindAmbiguousTypeNames(context.CurrentModule, internalsVisible: true);
 			foreach (AssemblyNameReference r in context.CurrentModule.AssemblyReferences) {
 				AssemblyDefinition d = context.CurrentModule.AssemblyResolver.Resolve(r);
diff --git a/ICSharpCode.Decompiler/DecompilerSettings.cs b/ICSharpCode.Decompiler/DecompilerSettings.cs
index 4ea54894d..c490cdb2a 100644
--- a/ICSharpCode.Decompiler/DecompilerSettings.cs
+++ b/ICSharpCode.Decompiler/DecompilerSettings.cs
@@ -140,6 +140,18 @@ namespace ICSharpCode.Decompiler
 			}
 		}
 		
+		bool fullyQualifyAmbiguousTypeNames = true;
+		
+		public bool FullyQualifyAmbiguousTypeNames {
+			get { return fullyQualifyAmbiguousTypeNames; }
+			set {
+				if (fullyQualifyAmbiguousTypeNames != value) {
+					fullyQualifyAmbiguousTypeNames = value;
+					OnPropertyChanged("FullyQualifyAmbiguousTypeNames");
+				}
+			}
+		}
+		
 		public event PropertyChangedEventHandler PropertyChanged;
 		
 		protected virtual void OnPropertyChanged(string propertyName)
diff --git a/ICSharpCode.Decompiler/Tests/DecompilerTestBase.cs b/ICSharpCode.Decompiler/Tests/DecompilerTestBase.cs
index dd9c285c4..304b1ed96 100644
--- a/ICSharpCode.Decompiler/Tests/DecompilerTestBase.cs
+++ b/ICSharpCode.Decompiler/Tests/DecompilerTestBase.cs
@@ -34,8 +34,10 @@ namespace ICSharpCode.Decompiler.Tests
 		/// <returns>The decompilation result of compiled source code.</returns>
 		static string RoundtripCode(string code)
 		{
+			DecompilerSettings settings = new DecompilerSettings();
+			settings.FullyQualifyAmbiguousTypeNames = false;
 			AssemblyDefinition assembly = Compile(code);
-			AstBuilder decompiler = new AstBuilder(new DecompilerContext(assembly.MainModule));
+			AstBuilder decompiler = new AstBuilder(new DecompilerContext(assembly.MainModule) { Settings = settings });
 			decompiler.AddAssembly(assembly);
 			new Helpers.RemoveCompilerAttribute().Run(decompiler.CompilationUnit);
 			StringWriter output = new StringWriter();
diff --git a/ICSharpCode.Decompiler/Tests/IncrementDecrement.cs b/ICSharpCode.Decompiler/Tests/IncrementDecrement.cs
index 8716b89d8..e4aa729c9 100644
--- a/ICSharpCode.Decompiler/Tests/IncrementDecrement.cs
+++ b/ICSharpCode.Decompiler/Tests/IncrementDecrement.cs
@@ -36,7 +36,7 @@ public class IncrementDecrement
 		}
 	}
 	
-	MyEnum enumField;
+	private IncrementDecrement.MyEnum enumField;
 	public static int StaticField;
 	
 	public static int StaticProperty
@@ -167,8 +167,8 @@ public class IncrementDecrement
 	
 	public void CompoundAssignEnum()
 	{
-		enumField |= IncrementDecrement.MyEnum.Two;
-		enumField &= ~IncrementDecrement.MyEnum.Four;
+		this.enumField |= IncrementDecrement.MyEnum.Two;
+		this.enumField &= ~IncrementDecrement.MyEnum.Four;
 	}
 	
 	public int PostIncrementInAddition(int i, int j)