diff --git a/samples/PortSD4AddInToSD5/WorkbenchSingletonIssueProvider.cs b/samples/PortSD4AddInToSD5/WorkbenchSingletonIssueProvider.cs
index da30bd945d..c6413536d4 100644
--- a/samples/PortSD4AddInToSD5/WorkbenchSingletonIssueProvider.cs
+++ b/samples/PortSD4AddInToSD5/WorkbenchSingletonIssueProvider.cs
@@ -12,6 +12,7 @@ using System.Linq;
 using ICSharpCode.NRefactory.CSharp;
 using ICSharpCode.NRefactory.CSharp.Refactoring;
 using ICSharpCode.NRefactory.PatternMatching;
+using ICSharpCode.NRefactory.Refactoring;
 using ICSharpCode.NRefactory.Semantics;
 using ICSharpCode.NRefactory.CSharp.Resolver;
 using ICSharpCode.SharpDevelop;