diff --git a/watch.cpp b/watch.cpp
index 89fef81..0efe300 100644
--- a/watch.cpp
+++ b/watch.cpp
@@ -65,7 +65,7 @@
     return fd;
 }
 
-int Watch::processEvents(sd_event_source* eventSource, int fd,
+int Watch::processEvents(sd_event_source* /*eventSource*/, int fd,
                          uint32_t retEvents, void* userData)
 {
     auto watch = static_cast<Watch*>(userData);