diff --git a/browser/components/preferences/in-content/search.js b/browser/components/preferences/in-content/search.js
index 9fd1c479a393..f9a814f76166 100644
--- a/browser/components/preferences/in-content/search.js
+++ b/browser/components/preferences/in-content/search.js
@@ -343,6 +343,11 @@ EngineStore.prototype = {
         this.moveEngine(this._getEngineByName(e.name), i);
       } else {
         // Otherwise, add it back to our internal store
+
+        // The search service removes the alias when an engine is hidden,
+        // so clear any alias we may have cached before unhiding the engine.
+        e.alias = "";
+
         this._engines.splice(i, 0, e);
         let engine = e.originalEngine;
         engine.hidden = false;
diff --git a/browser/components/preferences/search.js b/browser/components/preferences/search.js
index 250c6ca640e4..9af4068c2702 100644
--- a/browser/components/preferences/search.js
+++ b/browser/components/preferences/search.js
@@ -372,6 +372,11 @@ EngineStore.prototype = {
         this.moveEngine(this._getEngineByName(e.name), i);
       } else {
         // Otherwise, add it back to our internal store
+
+        // The search service removes the alias when an engine is hidden,
+        // so clear any alias we may have cached before unhiding the engine.
+        e.alias = "";
+
         this._engines.splice(i, 0, e);
         this._ops.push(new EngineUnhideOp(e, i));
         added++;