diff --git a/tests/src/psa_exercise_key.c b/tests/src/psa_exercise_key.c
index 61fc845b5..5cb2296df 100644
--- a/tests/src/psa_exercise_key.c
+++ b/tests/src/psa_exercise_key.c
@@ -791,7 +791,7 @@ int mbedtls_test_psa_exported_key_sanity_check(
         }
     } else
     if (PSA_KEY_TYPE_IS_DH_PUBLIC_KEY(type) || PSA_KEY_TYPE_IS_DH_KEY_PAIR(type)) {
-        TEST_ASSERT(exported_length <=
+        TEST_ASSERT(exported_length ==
                     PSA_EXPORT_PUBLIC_KEY_OUTPUT_SIZE(type, bits));
         TEST_ASSERT(exported_length <=
                     PSA_EXPORT_PUBLIC_KEY_MAX_SIZE);