diff --git a/src/vs/workbench/parts/files/electron-browser/fileCommands.ts b/src/vs/workbench/parts/files/electron-browser/fileCommands.ts
index 199d769c59d..81171db9d97 100644
--- a/src/vs/workbench/parts/files/electron-browser/fileCommands.ts
+++ b/src/vs/workbench/parts/files/electron-browser/fileCommands.ts
@@ -168,7 +168,7 @@ function saveAll(saveAllArguments: any, editorService: IEditorService, untitledE
 	editorGroupService.groups.forEach(g => {
 		g.editors.forEach(e => {
 			const resource = e.getResource();
-			if (untitledEditorService.isDirty(resource)) {
+			if (resource && untitledEditorService.isDirty(resource)) {
 				if (!groupIdToUntitledResourceInput.has(g.id)) {
 					groupIdToUntitledResourceInput.set(g.id, []);
 				}