diff --git a/library/oid.c b/library/oid.c
index 811d34324..3c27bfc73 100644
--- a/library/oid.c
+++ b/library/oid.c
@@ -901,7 +901,7 @@ static int oid_parse_number(unsigned int *num, const char **p, const char *bound
     *num = 0;
     while (*p < bound && **p >= '0' && **p <= '9') {
         ret = 0;
-        if (*num > (INT_MAX / 10)) {
+        if (*num > (UINT_MAX / 10)) {
             return MBEDTLS_ERR_ASN1_INVALID_DATA;
         }
         *num *= 10;