diff --git a/tests/suites/test_suite_pk.function b/tests/suites/test_suite_pk.function
index 478e7d9a0b..da79062028 100644
--- a/tests/suites/test_suite_pk.function
+++ b/tests/suites/test_suite_pk.function
@@ -1112,7 +1112,7 @@ exit:
 void pk_rsa_overflow()
 {
     mbedtls_pk_context pk;
-    size_t hash_len = SIZE_MAX, sig_len = SIZE_MAX;
+    size_t hash_len = UINT_MAX + 1, sig_len = UINT_MAX + 1;
     unsigned char hash[50], sig[100];
 
     if (SIZE_MAX <= UINT_MAX) {