diff --git a/include/kernel/io.h b/include/kernel/io.h
index be82998..edfe2c7 100644
--- a/include/kernel/io.h
+++ b/include/kernel/io.h
@@ -73,6 +73,8 @@
  * @returns the length of null-terminated string a.
  */
 uint strlen(char *a);
+uint strnlen(char *s, size_t len);
+int strncmp(char *a, char *b, size_t len);
 
 bool isdigit(char c);
 /**