diff --git a/src/include/switch_utils.h b/src/include/switch_utils.h
index e5f3b592dd..a9b9ac0281 100644
--- a/src/include/switch_utils.h
+++ b/src/include/switch_utils.h
@@ -321,7 +321,7 @@ static inline char *switch_sanitize_number(char *number)
 
 	while((q = strrchr(p, '@'))) *q = '\0';
  
-	for(i = 0; i < strlen(warp); i++) {
+	for(i = 0; i < (int)strlen(warp); i++) {
 		while(p && (q = strchr(p, warp[i]))) p = q + 1;
 	}