diff --git a/include/vsprintf.h b/include/vsprintf.h
index 490c96c..33d05aa 100644
--- a/include/vsprintf.h
+++ b/include/vsprintf.h
@@ -9,6 +9,7 @@
 #define __VSPRINTF_H
 
 #include <stdarg.h>
+#include <linux/types.h>
 
 ulong simple_strtoul(const char *cp, char **endp, unsigned int base);