diff --git a/dom/indexedDB/IDBCursor.cpp b/dom/indexedDB/IDBCursor.cpp
index 79e09af93c8a..370f6e2a27ba 100644
--- a/dom/indexedDB/IDBCursor.cpp
+++ b/dom/indexedDB/IDBCursor.cpp
@@ -505,8 +505,6 @@ void IDBCursor::ContinuePrimaryKey(JSContext* aCx, JS::Handle<JS::Value> aKey,
     key = tmp;
   }
 
-  const Key& sortKey = IsLocaleAware() ? mSortKey : mKey;
-
   if (key.IsUnset()) {
     aRv.Throw(NS_ERROR_DOM_INDEXEDDB_DATA_ERR);
     return;
@@ -526,6 +524,8 @@ void IDBCursor::ContinuePrimaryKey(JSContext* aCx, JS::Handle<JS::Value> aKey,
     return;
   }
 
+  const Key& sortKey = IsLocaleAware() ? mSortKey : mKey;
+
   switch (mDirection) {
     case NEXT:
       if (key < sortKey || (key == sortKey && primaryKey <= mPrimaryKey)) {