1 files changed, 1 insertions, 1 deletions
diff --git a/rt/tst-shm.c b/rt/tst-shm.c
index 92593bd273..457b075a38 100644
--- a/rt/tst-shm.c
+++ b/rt/tst-shm.c
@@ -73,7 +73,7 @@ worker (int write_now)
     error (EXIT_FAILURE, 0, "size incorrect");
 
   mem = mmap (NULL, 4000, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
-  if (mem == NULL)
+  if (mem == MAP_FAILED)
     error (EXIT_FAILURE, 0, "mmap failed");
 
   ts.tv_sec = 0;