diff --git a/src/isolated-run-button.ts b/src/isolated-run-button.ts
index 9af5588f92..2da44f2b8c 100644
--- a/src/isolated-run-button.ts
+++ b/src/isolated-run-button.ts
@@ -132,8 +132,6 @@ function computeMode(): ButtonMode {
       return 'downloading';
     case 'installing':
       return 'unzipping';
-    case 'missing':
-      return 'checking';
     case 'downloaded':
     case 'installed':
     default: