diff --git a/programs/test/udp_proxy.c b/programs/test/udp_proxy.c
index 0428d2888..258522003 100644
--- a/programs/test/udp_proxy.c
+++ b/programs/test/udp_proxy.c
@@ -562,7 +562,7 @@ static packet prev[MAX_DELAYED_MSG];
 
 void clear_pending( void )
 {
-    memset( &prev, 0, sizeof( packet ) );
+    memset( &prev, 0, sizeof( prev ) );
     prev_len = 0;
 }