diff --git a/glib/gthread-posix.c b/glib/gthread-posix.c
index 3f74aa4de..b38aaa540 100644
--- a/glib/gthread-posix.c
+++ b/glib/gthread-posix.c
@@ -1172,8 +1172,10 @@ void
 g_system_thread_set_name (const gchar *name)
 {
 #ifdef HAVE_SYS_PRCTL_H
+#ifdef PR_SET_NAME
   prctl (PR_SET_NAME, name, 0, 0, 0, 0);
 #endif
+#endif
 }
 
 /* {{{1 Epilogue */