diff --git a/packages/@aws-cdk/toolkit-lib/lib/api/notices/filter.ts b/packages/@aws-cdk/toolkit-lib/lib/api/notices/filter.ts
index 976c1c82e..1f2adb424 100644
--- a/packages/@aws-cdk/toolkit-lib/lib/api/notices/filter.ts
+++ b/packages/@aws-cdk/toolkit-lib/lib/api/notices/filter.ts
@@ -52,7 +52,7 @@ interface ActualComponent {
    * placeholders look like `{resolve:XYZ}`.
    *
    * If there is more than one component with the same dynamic name, they are
-   * joined by ','.
+   * joined by ' '.
    *
    * @default - Don't add to the set of dynamic values
    */
@@ -188,7 +188,7 @@ export class NoticesFilter {
    * Adds dynamic values from the given ActualComponents
    *
    * If there are multiple components with the same dynamic name, they are joined
-   * by a comma.
+   * by a space.
    */
   private addDynamicValues(comps: ActualComponent[], notice: FilteredNotice) {
     const dynamicValues: Record<string, string[]> = {};
@@ -199,7 +199,7 @@ export class NoticesFilter {
       }
     }
     for (const [key, values] of Object.entries(dynamicValues)) {
-      notice.addDynamicValue(key, values.join(','));
+      notice.addDynamicValue(key, values.join(' '));
     }
   }
 
diff --git a/packages/@aws-cdk/toolkit-lib/test/api/notices.test.ts b/packages/@aws-cdk/toolkit-lib/test/api/notices.test.ts
index 9e79c04df..c829f46c2 100644
--- a/packages/@aws-cdk/toolkit-lib/test/api/notices.test.ts
+++ b/packages/@aws-cdk/toolkit-lib/test/api/notices.test.ts
@@ -424,7 +424,7 @@ describe(NoticesFilter, () => {
         bootstrappedEnvironments: bootstrappedEnvironments,
       });
       expect((await filtered).map((f) => f.notice)).toEqual([BASIC_BOOTSTRAP_NOTICE]);
-      expect((await filtered).map((f) => f.format()).join('\n')).toContain('env1,env2');
+      expect((await filtered).map((f) => f.format()).join('\n')).toContain('env1 env2');
     });
 
     test('ignores invalid bootstrap versions', async () => {