diff -r c2d05cf1a062 -r a2757c6427cc tests/test_string.c
--- a/tests/test_string.c	Wed Dec 31 15:25:30 2025 +0100
+++ b/tests/test_string.c	Wed Dec 31 16:01:08 2025 +0100
@@ -343,7 +343,7 @@
 
     CX_TEST_DO {
         // the entire string
-        for (off_t i = 0; i < str.length; i++) {
+        for (off_t i = 0; i < (off_t) str.length; i++) {
             CX_TEST_ASSERT(cx_strat(str, i) == str.ptr[i]);
         }
         // the entire string backwards