diff --git a/ext/ldap/ldap.c b/ext/ldap/ldap.c
index b2b8650d504..52ce567097c 100644
--- a/ext/ldap/ldap.c
+++ b/ext/ldap/ldap.c
@@ -2235,7 +2235,7 @@ static void php_ldap_do_modify(INTERNAL_FUNCTION_PARAMETERS, int oper, int ext)
 	unsigned int attribute_index = 0;
 	ZEND_HASH_FOREACH_STR_KEY_VAL(attributes_ht, attribute, attribute_values) {
 		if (attribute == NULL) {
-			php_error_docref(NULL, E_WARNING, "Unknown attribute in the data");
+			zend_argument_value_error(3, "must be an associative array of attribute => values");
 			RETVAL_FALSE;
 			goto cleanup;
 		}
diff --git a/ext/ldap/tests/gh16136.phpt b/ext/ldap/tests/gh16136.phpt
index 14f21e3e757..9283402158c 100644
--- a/ext/ldap/tests/gh16136.phpt
+++ b/ext/ldap/tests/gh16136.phpt
@@ -25,6 +25,5 @@ try {
 }
 
 ?>
---EXPECTF--
-Warning: ldap_add(): Unknown attribute in the data in %s on line %d
-bool(false)
+--EXPECT--
+ValueError: ldap_add(): Argument #3 ($entry) must be an associative array of attribute => values
diff --git a/ext/ldap/tests/ldap_add_modify_delete_programming_errors.phpt b/ext/ldap/tests/ldap_add_modify_delete_programming_errors.phpt
index 1be5fec7556..88409226072 100644
--- a/ext/ldap/tests/ldap_add_modify_delete_programming_errors.phpt
+++ b/ext/ldap/tests/ldap_add_modify_delete_programming_errors.phpt
@@ -133,9 +133,7 @@ try {
 ?>
 --EXPECTF--
 ValueError: ldap_add(): Argument #3 ($entry) must not be empty
-
-Warning: ldap_add(): Unknown attribute in the data in %s on line %d
-bool(false)
+ValueError: ldap_add(): Argument #3 ($entry) must be an associative array of attribute => values
 
 Warning: ldap_add(): Add: Can't contact LDAP server in %s on line %d
 bool(false)