diff --git a/kern/libkern/string.h b/kern/libkern/string.h
index 62b05fd..bd152e3 100644
--- a/kern/libkern/string.h
+++ b/kern/libkern/string.h
@@ -2,6 +2,7 @@
 #define KERNEL_STRING_H
 
 #include <stdint.h>
+#include <stdlib.h>
 
 // void *memcpy(void *s1, const void *s2, size_t n);
 // void *memmove(void *s1, const void *s2, size_t n);