diff --git a/app/soapbox/features/compose/components/compose_form.js b/app/soapbox/features/compose/components/compose_form.js
index ae3500022..237d32584 100644
--- a/app/soapbox/features/compose/components/compose_form.js
+++ b/app/soapbox/features/compose/components/compose_form.js
@@ -89,6 +89,7 @@ class ComposeForm extends ImmutablePureComponent {
   handleKeyDown = (e) => {
     if (e.keyCode === 13 && (e.ctrlKey || e.metaKey)) {
       this.handleSubmit();
+      e.preventDefault(); // Prevent bubbling to other ComposeForm instances
     }
   }