diff --git a/library/pk.c b/library/pk.c
index 03c1e35..96b8ef9 100644
--- a/library/pk.c
+++ b/library/pk.c
@@ -514,9 +514,11 @@
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     const mbedtls_pk_rsassa_pss_options *pss_opts;
 
+#if SIZE_MAX > UINT_MAX
     if (md_alg == MBEDTLS_MD_NONE && UINT_MAX < hash_len) {
         return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
     }
+#endif
 
     if (options == NULL) {
         return MBEDTLS_ERR_PK_BAD_INPUT_DATA;