diff --git a/Adapter.hh b/Adapter.hh
index d93c66b..d22b5cb 100644
--- a/Adapter.hh
+++ b/Adapter.hh
@@ -30,6 +30,8 @@ namespace pEp {
     };
 
     namespace Adapter {
+        int _inject_sync_event(SYNC_EVENT ev, void *management);
+
         template<class T = void>
         void startup(
                 messageToSend_t messageToSend,