diff --git a/include/ontologenius/API/ontologenius/PatternsSubscriber.h b/include/ontologenius/API/ontologenius/PatternsSubscriber.h
index 765437dd..d7b4cedd 100644
--- a/include/ontologenius/API/ontologenius/PatternsSubscriber.h
+++ b/include/ontologenius/API/ontologenius/PatternsSubscriber.h
@@ -6,6 +6,7 @@
 #include <functional>
 #include <string>
 #include <thread>
+#include <unordered_map>
 #include <vector>
 
 #include "ontologenius/compat/ros.h"