diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index 28a95e9fa7991..72f72fae87366 100644
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -30087,7 +30087,7 @@ cp_parser_contract_attribute_spec (cp_parser *parser, tree attribute,
     }
   else
     {
-      parens.consume_open (parser);
+      parens.require_open (parser);
       if (postcondition_p && cp_lexer_next_token_is (parser->lexer, CPP_NAME)
 	  && cp_lexer_peek_nth_token (parser->lexer, 2)->type == CPP_COLON)
 	identifier = cp_parser_identifier (parser);
diff --git a/gcc/testsuite/g++.dg/contracts/new/contracts1.C b/gcc/testsuite/g++.dg/contracts/new/contracts1.C
index a74dd5ac07115..63a308b868d9f 100644
--- a/gcc/testsuite/g++.dg/contracts/new/contracts1.C
+++ b/gcc/testsuite/g++.dg/contracts/new/contracts1.C
@@ -27,6 +27,7 @@ int g2(int a) [[pre: f(a) > a ]]
 }
 
 int fun(int n)  pre (n > 0 );
+void fun2(int n)  pre  n > 0 ]]; // { dg-error  }
 void fun2(int n)  pre (: n > 0 ]]; // { dg-error  }
 int fun3(int n)  [[ pre : n > 0 ); // { dg-error "expected .]. before " }