Index: lib/Sema/SemaCoroutine.cpp
===================================================================
--- lib/Sema/SemaCoroutine.cpp
+++ lib/Sema/SemaCoroutine.cpp
@@ -13,6 +13,7 @@
 
 #include "CoroutineStmtBuilder.h"
 #include "clang/AST/Decl.h"
+#include "clang/AST/DeclCXX.h"
 #include "clang/AST/ExprCXX.h"
 #include "clang/AST/StmtCXX.h"
 #include "clang/Lex/Preprocessor.h"
@@ -43,9 +44,10 @@
 
 /// Look up the std::coroutine_traits<...>::promise_type for the given
 /// function type.
-static QualType lookupPromiseType(Sema &S, const FunctionProtoType *FnType,
+static QualType lookupPromiseType(Sema &S, const FunctionDecl *FD,
                                   SourceLocation KwLoc,
                                   SourceLocation FuncLoc) {
+  const FunctionProtoType *FnType = FD->getType()->castAs<FunctionProtoType>();
   // FIXME: Cache std::coroutine_traits once we've found it.
   NamespaceDecl *StdExp = S.lookupStdExperimentalNamespace();
   if (!StdExp) {
@@ -76,8 +78,15 @@
   Args.addArgument(TemplateArgumentLoc(
       TemplateArgument(FnType->getReturnType()),
       S.Context.getTrivialTypeSourceInfo(FnType->getReturnType(), KwLoc)));
-  // FIXME: If the function is a non-static member function, add the type
+  // If the function is a non-static member function, add the type
   // of the implicit object parameter before the formal parameters.
+  if (auto *MD = dyn_cast_or_null<CXXMethodDecl>(FD)) {
+    if (MD->isInstance()) {
+      QualType T = MD->getThisType(S.Context);
+      Args.addArgument(TemplateArgumentLoc(
+          TemplateArgument(T), S.Context.getTrivialTypeSourceInfo(T, KwLoc)));
+    }
+  }
   for (QualType T : FnType->getParamTypes())
     Args.addArgument(TemplateArgumentLoc(
         TemplateArgument(T), S.Context.getTrivialTypeSourceInfo(T, KwLoc)));
@@ -424,12 +433,17 @@
 VarDecl *Sema::buildCoroutinePromise(SourceLocation Loc) {
   assert(isa<FunctionDecl>(CurContext) && "not in a function scope");
   auto *FD = cast<FunctionDecl>(CurContext);
+  bool IsThisDependentType = [&] {
+    if (auto *MD = dyn_cast_or_null<CXXMethodDecl>(FD))
+      return MD->isInstance() && MD->getThisType(Context)->isDependentType();
+    else
+      return false;
+  }();
 
   QualType T =
-      FD->getType()->isDependentType()
+      FD->getType()->isDependentType() || IsThisDependentType
           ? Context.DependentTy
-          : lookupPromiseType(*this, FD->getType()->castAs<FunctionProtoType>(),
-                              Loc, FD->getLocation());
+          : lookupPromiseType(*this, FD, Loc, FD->getLocation());
   if (T.isNull())
     return nullptr;
 
Index: test/SemaCXX/coroutine-nonstatic-member-function.cpp
===================================================================
--- /dev/null
+++ test/SemaCXX/coroutine-nonstatic-member-function.cpp
@@ -0,0 +1,34 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin9 %s -std=c++1z -fcoroutines-ts -fsyntax-only -Wall -Wextra -Wuninitialized  -fblocks
+#include "Inputs/std-coroutine.h"
+
+using namespace std::experimental;
+
+struct coro_t {};
+
+struct coro_promise_type {
+  coro_t get_return_object() { return {}; }
+  suspend_never initial_suspend() { return {}; }
+  suspend_never final_suspend() { return {}; }
+  void return_void() {}
+  static void unhandled_exception() {}
+};
+
+struct C {
+  coro_t f();
+};
+
+namespace std::experimental {
+  template<>
+  struct coroutine_traits<coro_t, C*> {
+    using promise_type = coro_promise_type;
+  };
+}
+
+coro_t C::f() {
+  co_return;
+}
+
+int main() {
+  C c;
+  c.f();
+}