diff --git a/glib/tests/thread.c b/glib/tests/thread.c
index b80019009..b9f87967b 100644
--- a/glib/tests/thread.c
+++ b/glib/tests/thread.c
@@ -21,6 +21,7 @@
  */
 
 #include <config.h>
+#include <errno.h>
 
 #ifdef HAVE_SYS_TIME_H
 #include <sys/time.h>
@@ -146,8 +147,8 @@ test_thread4 (void)
   getrlimit (RLIMIT_NPROC, &nl);
   nl.rlim_cur = 1;
 
-  if ((ret = prlimit (getpid(), RLIMIT_NPROC, &nl, &ol)) != 0)
-    g_error ("prlimit failed: %s", g_strerror (ret));
+  if ((ret = prlimit (getpid (), RLIMIT_NPROC, &nl, &ol)) != 0)
+    g_error ("prlimit failed: %s", g_strerror (errno));
 
   error = NULL;
   thread = g_thread_try_new ("a", thread1_func, NULL, &error);
@@ -156,7 +157,7 @@ test_thread4 (void)
   g_error_free (error);
 
   if ((ret = prlimit (getpid (), RLIMIT_NPROC, &ol, NULL)) != 0)
-    g_error ("resetting RLIMIT_NPROC failed: %s", g_strerror (ret));
+    g_error ("resetting RLIMIT_NPROC failed: %s", g_strerror (errno));
 #endif
 }