diff --git a/mm/nommu.c b/mm/nommu.c
index c8bd59a..c2e588802 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1682,7 +1682,7 @@
 	}
 }
 
-unsigned long vm_brk(unsigned long addr, unsigned long len)
+int vm_brk(unsigned long addr, unsigned long len)
 {
 	return -ENOMEM;
 }