diff --git a/memcheck/tests/linux/sigqueue.c b/memcheck/tests/linux/sigqueue.c
index 138a27602..65f4403a8 100644
--- a/memcheck/tests/linux/sigqueue.c
+++ b/memcheck/tests/linux/sigqueue.c
@@ -1,3 +1,5 @@
+/* Test program that invokes the Linux system call rt_sigqueueinfo(). */
+
 #include <signal.h>
 #include <string.h>
 #include <stddef.h>