diff --git a/dump_manager.hpp b/dump_manager.hpp
index 4b5005d..40f62fb 100644
--- a/dump_manager.hpp
+++ b/dump_manager.hpp
@@ -139,7 +139,7 @@
      *
      *  @returns 0 on success, -1 on fail
      */
-    static int callback(sd_event_source* s, const siginfo_t* si, void* userdata)
+    static int callback(sd_event_source*, const siginfo_t*, void*)
     {
         // No specific action required in
         // the sd_event_add_child callback.