diff --git a/CHANGELOG.md b/CHANGELOG.md
index ebdffb551..8fee3c232 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## Fixed
 - [client] Added circular JSON handling to `forwardToMain.ts` which fixed a bug preventing the Emulator from connecting to Direct Line Speech bots in PR [2242](https://github.com/microsoft/BotFramework-Emulator/pull/2242)
 - [client/main] Fixed an issue where the Emulator was failing to detect the final redirect URL when trying to login to Azure in PR [2248](https://github.com/microsoft/BotFramework-Emulator/pull/2248)
+- [client] Fixed an issue where the Custom Activity Editor was sending the default model content instead of what was currently being displayed in the editor in PR [2255](https://github.com/microsoft/BotFramework-Emulator/pull/2255)
 
 ## v4.12.0 - 2021 - 3 - 05
 ## Added
diff --git a/packages/app/client/src/ui/dialogs/customActivityEditor/customActivityEditor.tsx b/packages/app/client/src/ui/dialogs/customActivityEditor/customActivityEditor.tsx
index 65cc9ed55..3c07bd523 100644
--- a/packages/app/client/src/ui/dialogs/customActivityEditor/customActivityEditor.tsx
+++ b/packages/app/client/src/ui/dialogs/customActivityEditor/customActivityEditor.tsx
@@ -85,6 +85,9 @@ export const CustomActivityEditor: React.FC<CustomActivityEditorProps> = (props:
       // warnings are 4 and errors are 8
       setIsValid(!markers.some(m => m.severity >= monaco.MarkerSeverity.Warning));
     });
+    // the editor's model may still have leftover content from the last time it was rendered;
+    // send it back through the onDidChangeModelContent handler so that it gets set in the React state
+    editor.setValue(editor.getValue());
   }, []);
 
   const onSendActivityClick = useCallback(() => {