diff --git a/src/AddIns/Misc/CodeAnalysis/Src/FxCopLogger.cs b/src/AddIns/Misc/CodeAnalysis/Src/FxCopLogger.cs
index cc496cc8b1..3cb671c2d7 100644
--- a/src/AddIns/Misc/CodeAnalysis/Src/FxCopLogger.cs
+++ b/src/AddIns/Misc/CodeAnalysis/Src/FxCopLogger.cs
@@ -7,6 +7,7 @@
 
 using System;
 using System.IO;
+using ICSharpCode.Core;
 using ICSharpCode.SharpDevelop;
 using ICSharpCode.SharpDevelop.Dom;
 using ICSharpCode.SharpDevelop.Project;
@@ -85,7 +86,8 @@ namespace ICSharpCode.CodeAnalysis
 			{
 				string[] moreData = (subcategory ?? "").Split('|');
 				BuildError err = engine.CurrentErrorOrWarning;
-				if (Path.GetFileName(file) == "SharpDevelop.CodeAnalysis.targets") {
+				if (FileUtility.IsValidFileName(file) &&
+				    Path.GetFileName(file) == "SharpDevelop.CodeAnalysis.targets") {
 					err.FileName = null;
 				}
 				IProject project = ProjectService.GetProject(engine.CurrentProjectFile);
diff --git a/src/Main/Base/Project/Src/Project/MSBuildEngine.cs b/src/Main/Base/Project/Src/Project/MSBuildEngine.cs
index 066dbc05e6..a80e31360b 100644
--- a/src/Main/Base/Project/Src/Project/MSBuildEngine.cs
+++ b/src/Main/Base/Project/Src/Project/MSBuildEngine.cs
@@ -371,7 +371,7 @@ namespace ICSharpCode.SharpDevelop.Project
 			{
 				if (string.Equals(file, activeTaskName, StringComparison.InvariantCultureIgnoreCase)) {
 					file = "";
-				} else {
+				} else if (FileUtility.IsValidFileName(file)) {
 					bool isShortFileName = file == Path.GetFileNameWithoutExtension(file);
 					if (engine.CurrentProjectFile != null) {
 						file = Path.Combine(Path.GetDirectoryName(engine.CurrentProjectFile), file);