Index: clang/lib/Sema/SemaCoroutine.cpp
===================================================================
--- clang/lib/Sema/SemaCoroutine.cpp
+++ clang/lib/Sema/SemaCoroutine.cpp
@@ -977,19 +977,25 @@
     E = R.get();
   }
 
+  Expr *PCE = nullptr;
   VarDecl *Promise = FSI->CoroutinePromise;
-  ExprResult PC;
-  if (E && (isa<InitListExpr>(E) || !E->getType()->isVoidType())) {
-    getNamedReturnInfo(E, SimplerImplicitMoveMode::ForceOn);
-    PC = buildPromiseCall(*this, Promise, Loc, "return_value", E);
+  if ((E && E->getType()->isDependentType()) ||
+      Promise->getType()->isDependentType()) {
+    // It is dependent, do nothing until instantiation time.
   } else {
-    E = MakeFullDiscardedValueExpr(E).get();
-    PC = buildPromiseCall(*this, Promise, Loc, "return_void", None);
-  }
-  if (PC.isInvalid())
-    return StmtError();
+    ExprResult PC;
+    if (E && (isa<InitListExpr>(E) || !E->getType()->isVoidType())) {
+      getNamedReturnInfo(E, SimplerImplicitMoveMode::ForceOn);
+      PC = buildPromiseCall(*this, Promise, Loc, "return_value", E);
+    } else {
+      E = MakeFullDiscardedValueExpr(E).get();
+      PC = buildPromiseCall(*this, Promise, Loc, "return_void", None);
+    }
+    if (PC.isInvalid())
+      return StmtError();
 
-  Expr *PCE = ActOnFinishFullExpr(PC.get(), /*DiscardedValue*/ false).get();
+    PCE = ActOnFinishFullExpr(PC.get(), /*DiscardedValue*/ false).get();
+  }
 
   Stmt *Res = new (Context) CoreturnStmt(Loc, E, PCE, IsImplicit);
   return Res;
Index: clang/test/SemaCXX/coroutine-dep.cpp
===================================================================
--- /dev/null
+++ clang/test/SemaCXX/coroutine-dep.cpp
@@ -0,0 +1,70 @@
+// RUN: %clang_cc1 -std=c++17 -fcoroutines-ts -fsyntax-only %s
+
+namespace std {
+template <typename _Result, typename...>
+struct coroutine_traits {
+  using promise_type = typename _Result::promise_type;
+};
+
+template <typename _Promise = void>
+struct coroutine_handle;
+
+template <>
+struct coroutine_handle<void> {
+  static coroutine_handle from_address(void *__a) noexcept;
+  void resume() const noexcept;
+  void destroy() const noexcept;
+};
+
+template <typename _Promise>
+struct coroutine_handle : coroutine_handle<> {};
+
+struct suspend_always {
+  bool await_ready() const noexcept;
+  void await_suspend(coroutine_handle<>) const noexcept;
+  void await_resume() const noexcept;
+};
+} // namespace std
+
+namespace Void {
+class Task {
+public:
+  struct promise_type {
+  public:
+    std::suspend_always initial_suspend() noexcept;
+    std::suspend_always final_suspend() noexcept;
+
+    Task get_return_object() noexcept;
+    void unhandled_exception() noexcept;
+    void return_void() noexcept;
+  };
+};
+
+template <typename T>
+Task Foo() noexcept {
+  co_return T(0);
+  ;
+}
+template Task Foo<void>() noexcept;
+} // namespace Void
+
+namespace Value {
+class Task {
+public:
+  struct promise_type {
+  public:
+    std::suspend_always initial_suspend() noexcept;
+    std::suspend_always final_suspend() noexcept;
+
+    Task get_return_object() noexcept;
+    void unhandled_exception() noexcept;
+    void return_value(int value) noexcept;
+  };
+};
+
+template <typename T>
+Task Foo() noexcept {
+  co_return T(0);
+}
+template Task Foo<int>() noexcept;
+} // namespace Value