1 files changed, 3 insertions, 5 deletions
diff --git a/src/fields/Doc.ts b/src/fields/Doc.ts
index 7a1ab3b4f..74f18cbc8 100644
--- a/src/fields/Doc.ts
+++ b/src/fields/Doc.ts
@@ -97,9 +97,8 @@ export namespace Field {
         });
         return script;
     }
-    export function toString(fieldIn: unknown) {
-        const field = fieldIn as FieldType;
-        if (typeof field === 'string' || typeof field === 'number' || typeof field === 'boolean') return String(field);
+    export function toString(field: FieldResult<FieldType> | FieldType | undefined) {
+        if (field instanceof Promise || typeof field === 'string' || typeof field === 'number' || typeof field === 'boolean') return String(field);
         return field?.[ToString]?.() || '';
     }
     export function IsField(field: unknown): field is FieldType;
@@ -111,7 +110,7 @@ export namespace Field {
     export function Copy(field: unknown) {
         return field instanceof ObjectField ? ObjectField.MakeCopy(field) : (field as FieldType);
     }
-    UndoManager.SetFieldPrinter(toString);
+    UndoManager.SetFieldPrinter((val: unknown) => (IsField(val) ? toString(val) : ''));
 }
 export type FieldType = number | string | boolean | ObjectField | RefField;
 export type Opt<T> = T | undefined;
@@ -463,7 +462,6 @@ export class Doc extends RefField {
             });
     }
 }
-
 export namespace Doc {
     export let SelectOnLoad: Doc | undefined;
     export function SetSelectOnLoad(doc: Doc | undefined) {