diff --git a/src/install-dialog.ts b/src/install-dialog.ts
index b4a2170..98828d2 100644
--- a/src/install-dialog.ts
+++ b/src/install-dialog.ts
@@ -397,6 +397,8 @@ class EwtInstallDialog extends LitElement {
           break;
 
         case ImprovSerialErrorState.NO_ERROR:
+        // Happens when list SSIDs not supported.
+        case ImprovSerialErrorState.UNKNOWN_RPC_COMMAND:
           break;
 
         default: