diff --git a/src/lib/string.c b/src/lib/string.c
index b1996ff..a7f8074 100644
--- a/src/lib/string.c
+++ b/src/lib/string.c
@@ -115,7 +115,7 @@
 
 int strncmp(const char *s1, const char *s2, size_t maxlen)
 {
-	int i;
+	size_t i;
 
 	for (i = 0; i < maxlen; i++) {
 		if ((s1[i] != s2[i]) || (s1[i] == '\0'))