diff --git a/tests/include/test/psa_crypto_helpers.h b/tests/include/test/psa_crypto_helpers.h
index 9881eae..522fbae 100644
--- a/tests/include/test/psa_crypto_helpers.h
+++ b/tests/include/test/psa_crypto_helpers.h
@@ -186,6 +186,14 @@
 
 #endif /* defined(RECORD_PSA_STATUS_COVERAGE_LOG) */
 
+/** Return extended key usage policies.
+ *
+ * Do a key policy permission extension on key usage policies always involves
+ * permissions of other usage policies
+ * (like PSA_KEY_USAGE_SIGN_HASH involves PSA_KEY_USAGE_SIGN_MESSGAE).
+ */
+psa_key_usage_t update_key_usage_flags( psa_key_usage_t usage_flags );
+
 /** Skip a test case if the given key is a 192 bits AES key and the AES
  *  implementation is at least partially provided by an accelerator or
  *  alternative implementation.