Index: uspace/lib/libc/generic/futex.c
===================================================================
--- uspace/lib/libc/generic/futex.c	(revision f74392fe9cc78a9b01eddaa13d2ad744f4907a1e)
+++ uspace/lib/libc/generic/futex.c	(revision 228666c006a3414de772f08f77335c546dd21aab)
@@ -68,5 +68,5 @@
 int futex_down(futex_t *futex)
 {
-	if (atomic_predec(futex) < 0)
+	if ((atomic_signed_t) atomic_predec(futex) < 0)
 		return __SYSCALL1(SYS_FUTEX_SLEEP, (sysarg_t) &futex->count);
 
@@ -82,5 +82,5 @@
 int futex_up(futex_t *futex)
 {
-	if (atomic_postinc(futex) < 0)
+	if ((atomic_signed_t) atomic_postinc(futex) < 0)
 		return __SYSCALL1(SYS_FUTEX_WAKEUP, (sysarg_t) &futex->count);