Index: clang/lib/Parse/ParseExprCXX.cpp
===================================================================
--- clang/lib/Parse/ParseExprCXX.cpp
+++ clang/lib/Parse/ParseExprCXX.cpp
@@ -3589,7 +3589,7 @@
 
           // We need to consume the typename to allow 'requires { typename a; }'
           SourceLocation TypenameKWLoc = ConsumeToken();
-          if (TryAnnotateCXXScopeToken()) {
+          if (TryAnnotateOptionalCXXScopeToken()) {
             TPA.Commit();
             SkipUntil(tok::semi, tok::r_brace, SkipUntilFlags::StopBeforeMatch);
             break;
Index: clang/test/Parser/cxx2a-concepts-requires-expr.cpp
===================================================================
--- clang/test/Parser/cxx2a-concepts-requires-expr.cpp
+++ clang/test/Parser/cxx2a-concepts-requires-expr.cpp
@@ -144,3 +144,18 @@
 
 bool r41 = requires { requires (); };
 // expected-error@-1 {{expected expression}}
+
+bool r42 = requires { typename long; }; // expected-error {{expected a qualified name after 'typename'}}
+
+template <int N>
+requires requires {
+ typename _BitInt(N); // expected-error {{expected a qualified name after 'typename'}}
+} using r43 = void;
+
+template <int N>
+using BitInt = _BitInt(N);
+
+template <int N>
+requires requires {
+ typename BitInt<N>; // ok
+} using r44 = void;