diff --git a/st.c b/st.c
index 6a943b8ddd..77d998f9fc 100644
--- a/st.c
+++ b/st.c
@@ -2036,7 +2036,7 @@ int
 st_locale_insensitive_strncasecmp(const char *s1, const char *s2, size_t n)
 {
     char c1, c2;
-    int i;
+    size_t i;
 
     for (i = 0; i < n; i++) {
         c1 = *s1++;