diff --git a/src/crl.c b/src/crl.c
index e55f68287..939fbd3b6 100644
--- a/src/crl.c
+++ b/src/crl.c
@@ -476,7 +476,7 @@ static void* DoMonitor(void* arg)
 /* shutdown monitor thread, 0 on success */
 static int StopMonitor(int mfd)
 {
-
+    (void)mfd;
 
     return -1;
 }