diff --git a/sys/libc/include/sys/uio.h b/sys/libc/include/sys/uio.h
index 8ee74b0f42..c3e4d8e234 100644
--- a/sys/libc/include/sys/uio.h
+++ b/sys/libc/include/sys/uio.h
@@ -20,6 +20,7 @@
 #ifndef UIO_H
 #define UIO_H
 
+#include <stdlib.h>
 #include <sys/types.h>
 
 #ifdef __cplusplus