diff --git a/pkgs/racket-test-core/tests/racket/unix_check.c b/pkgs/racket-test-core/tests/racket/unix_check.c
index f7f7ade103..95cb4cd351 100644
--- a/pkgs/racket-test-core/tests/racket/unix_check.c
+++ b/pkgs/racket-test-core/tests/racket/unix_check.c
@@ -11,7 +11,7 @@ int main()
   int i;
 
   /* SIGPROF tends to be near the end of the range of signal IDs */
-  for (i = 0; i < SIGPROF; i++) {
+  for (i = 1; i < SIGPROF; i++) {
     sigaction(i, NULL, &sa);
     if (sa.sa_handler != SIG_DFL)
       return 1;