diff --git a/src/interactive-auth.js b/src/interactive-auth.js
index 058d82796..f7ebcdca8 100644
--- a/src/interactive-auth.js
+++ b/src/interactive-auth.js
@@ -334,15 +334,6 @@ InteractiveAuth.prototype = {
      */
     _chooseStage: function() {
         const flow = this._chooseFlow();
-        if (!flow) {
-            // XXX: This happens to be the only way this can fail right now, but
-            // in general this is not really going to be an accurate error message.
-            // Ideally this would signal what inputs could be removed such that a matching
-            // flow could be found.
-            throw new Error(
-                "This server does not support registration with a phone number",
-            );
-        }
         console.log("Active flow => %s", JSON.stringify(flow));
         const nextStage = this._firstUncompletedStage(flow);
         console.log("Next stage: %s", nextStage);
@@ -388,7 +379,13 @@ InteractiveAuth.prototype = {
                 return flow;
             }
         }
-        return null;
+        // XXX: This happens to be the only way this can fail right now, but
+        // in general this is not really going to be an accurate error message.
+        // Ideally this would signal what inputs could be removed such that a matching
+        // flow could be found.
+        throw new Error(
+            "This server does not support registration with a phone number",
+        );
     },
 
     /**