diff --git a/src/VisualStudio/Core/Def/Implementation/ProjectSystem/VisualStudioWorkspace.cs b/src/VisualStudio/Core/Def/Implementation/ProjectSystem/VisualStudioWorkspace.cs
index 52290b2b5653db1eefb706e78f901cb2c000542d..5af8136f976fae506ff38d56c6ec840fdd58a978 100644
--- a/src/VisualStudio/Core/Def/Implementation/ProjectSystem/VisualStudioWorkspace.cs
+++ b/src/VisualStudio/Core/Def/Implementation/ProjectSystem/VisualStudioWorkspace.cs
@@ -85,7 +85,9 @@ protected override void OnDocumentClosing(DocumentId documentId)
 
         public virtual string GetFilePath(DocumentId documentId)
         {
-            return CurrentSolution.GetDocument(documentId)?.FilePath;
+            var solution = CurrentSolution;
+
+            return (solution.GetDocument(documentId) ?? solution.GetAdditionalDocument(documentId))?.FilePath;
         }
 
         /// <summary>
diff --git a/src/VisualStudio/Core/Def/Implementation/ProjectSystem/VisualStudioWorkspaceImpl.cs b/src/VisualStudio/Core/Def/Implementation/ProjectSystem/VisualStudioWorkspaceImpl.cs
index f1a5a4ec42a70925fd367969869eaa49d0e8c021..45bc43766055157536264b1867131a020f5f0a26 100644
--- a/src/VisualStudio/Core/Def/Implementation/ProjectSystem/VisualStudioWorkspaceImpl.cs
+++ b/src/VisualStudio/Core/Def/Implementation/ProjectSystem/VisualStudioWorkspaceImpl.cs
@@ -267,7 +267,7 @@ internal IVisualStudioHostDocument GetHostDocument(DocumentId documentId)
             }
 
             // first make sure we can edit the document we will be updating (check them out from source control, etc)
-            var changedDocs = projectChanges.SelectMany(pd => pd.GetChangedDocuments(true)).ToList();
+            var changedDocs = projectChanges.SelectMany(pd => pd.GetChangedDocuments(true).Concat(pd.GetChangedAdditionalDocuments())).ToList();
             if (changedDocs.Count > 0)
             {
                 this.EnsureEditableDocuments(changedDocs);