diff --git a/Codist/NaviBar/NaviBarFactory.cs b/Codist/NaviBar/NaviBarFactory.cs
index 454ea693..26424a46 100644
--- a/Codist/NaviBar/NaviBarFactory.cs
+++ b/Codist/NaviBar/NaviBarFactory.cs
@@ -44,7 +44,7 @@ public void TextViewCreated(IWpfTextView textView) {
 
 		static void AssociateFileCodeModelOverrider() {
 			Microsoft.VisualStudio.Shell.ThreadHelper.ThrowIfNotOnUIThread();
-			var model = CodistPackage.DTE2.ActiveDocument?.ProjectItem.FileCodeModel; // the active document can be null
+			var model = CodistPackage.DTE2.ActiveDocument?.ProjectItem?.FileCodeModel; // the active document can be null
 			if (model == null) {
 				return;
 			}