diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 940751b5f05..dfc9b8251a7 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -28530,7 +28530,20 @@ cp_parser_constraint_requires_parens (cp_parser *parser, bool lambda_p)
       case CPP_PLUS_PLUS:
       case CPP_MINUS_MINUS:
       case CPP_DOT:
+	/* Unenclosed postfix operator.  */
+	return pce_maybe_postfix;
+
       case CPP_DEREF:
+	/* A primary constraint that precedes the lambda-declarator of a
+	   lambda expression is followed by trailing return type.
+
+	      []<typename T> requires C -> void {}
+
+	   Don't try to re-parse this as a postfix expression in
+	   C++23 and later.  In C++20 ( needs to come in between but we
+	   allow it to be omitted with pedwarn.  */
+	if (lambda_p)
+	  return pce_ok;
 	/* Unenclosed postfix operator.  */
 	return pce_maybe_postfix;
    }
diff --git a/gcc/testsuite/g++.dg/cpp23/lambda-specifiers2.C b/gcc/testsuite/g++.dg/cpp23/lambda-specifiers2.C
new file mode 100644
index 00000000000..0cc69bebc64
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp23/lambda-specifiers2.C
@@ -0,0 +1,7 @@
+// PR c++/99850
+// P1102R2 - Down with ()!
+// { dg-do compile { target c++23 } }
+
+auto l = []<auto> requires true -> void {};
+template <typename...> concept C = true;
+auto m = []<typename... Ts> requires (C<Ts> && ...) -> void {};