diff --git a/src/vs/workbench/parts/debug/browser/debugEditorModelManager.ts b/src/vs/workbench/parts/debug/browser/debugEditorModelManager.ts
index 864b9f2529b7c49415ee5e6ecad1ffe53d1ba20c..3d9510afb956773d3ac3c51c0d2014a57dfee4c2 100644
--- a/src/vs/workbench/parts/debug/browser/debugEditorModelManager.ts
+++ b/src/vs/workbench/parts/debug/browser/debugEditorModelManager.ts
@@ -292,7 +292,7 @@ export class DebugEditorModelManager implements IWorkbenchContribution {
 		}
 
 		if (!session || session.configuration.capabilities.supportsConditionalBreakpoints) {
-			const mode = modelData.model.getMode();
+			const mode = modelData ? modelData.model.getMode() : null;
 			const modeId = mode ? mode.getId() : '';
 			const glyphMarginHoverMessage = `\`\`\`${modeId}\n${ breakpoint.condition }\`\`\``;