diff --git a/src/vs/workbench/api/node/extHostDocumentsAndEditors.ts b/src/vs/workbench/api/node/extHostDocumentsAndEditors.ts
index 3aa410ad1e1..4048e3a936b 100644
--- a/src/vs/workbench/api/node/extHostDocumentsAndEditors.ts
+++ b/src/vs/workbench/api/node/extHostDocumentsAndEditors.ts
@@ -101,7 +101,7 @@ export class ExtHostDocumentsAndEditors implements ExtHostDocumentsAndEditorsSha
 					data.selections.map(typeConverters.Selection.to),
 					data.options,
 					data.visibleRanges.map(typeConverters.Range.to),
-					typeof data.editorPosition === 'undefined' ? undefined : typeConverters.ViewColumn.to(data.editorPosition)
+					typeof data.editorPosition === 'number' ? typeConverters.ViewColumn.to(data.editorPosition) : undefined
 				);
 				this._editors.set(data.id, editor);
 			}
diff --git a/src/vs/workbench/api/node/extHostWebview.ts b/src/vs/workbench/api/node/extHostWebview.ts
index 0906dd92aad..f3851ed6088 100644
--- a/src/vs/workbench/api/node/extHostWebview.ts
+++ b/src/vs/workbench/api/node/extHostWebview.ts
@@ -333,7 +333,7 @@ export class ExtHostWebviews implements ExtHostWebviewsShape {
 		}
 
 		const webview = new ExtHostWebview(webviewHandle, this._proxy, options);
-		const revivedPanel = new ExtHostWebviewPanel(webviewHandle, this._proxy, viewType, title, typeConverters.ViewColumn.to(position), options, webview);
+		const revivedPanel = new ExtHostWebviewPanel(webviewHandle, this._proxy, viewType, title, typeof position === 'number' ? typeConverters.ViewColumn.to(position) : undefined, options, webview);
 		this._webviewPanels.set(webviewHandle, revivedPanel);
 		return Promise.resolve(serializer.deserializeWebviewPanel(revivedPanel, state));
 	}