diff --git a/src/kernel/io.c b/src/kernel/io.c
index baa050f..0b300b5 100644
--- a/src/kernel/io.c
+++ b/src/kernel/io.c
@@ -55,8 +55,8 @@
 
 uint strlen(char *a)
 {
-	int i = 0;
-	for (; *a; i++)
+	uint i = 0;
+	for (; a[i]; i++)
 	{
 	}