diff --git a/extras/Projucer/Source/Project/UI/Sidebar/jucer_ModuleTreeItems.h b/extras/Projucer/Source/Project/UI/Sidebar/jucer_ModuleTreeItems.h
index 708e25a462..3610671156 100644
--- a/extras/Projucer/Source/Project/UI/Sidebar/jucer_ModuleTreeItems.h
+++ b/extras/Projucer/Source/Project/UI/Sidebar/jucer_ModuleTreeItems.h
@@ -626,6 +626,7 @@ public:
         }
 
         auto ids = list.getIDs();
+        ids.removeDuplicates (false);
 
         for (auto m : getAvailableModulesInGlobalJucePath())
             ids.removeString (m);