Set up poll overrides
diff --git a/test/cpp/end2end/async_end2end_test.cc b/test/cpp/end2end/async_end2end_test.cc
index 78417fc..aa99061 100644
--- a/test/cpp/end2end/async_end2end_test.cc
+++ b/test/cpp/end2end/async_end2end_test.cc
@@ -67,10 +67,10 @@
 void* tag(int i) { return (void*)(intptr_t)i; }
 
 #ifdef GPR_POSIX_SOCKET
-static int assert_non_blocking_poll(struct pollfd* pfds, nfds_t nfds,
+static int non_blocking_poll(struct pollfd* pfds, nfds_t nfds,
                                     int timeout) {
-  GPR_ASSERT(timeout == 0);
-  return poll(pfds, nfds, timeout);
+  /* ignore timeout and always use timeout 0 */
+  return poll(pfds, nfds, 0);
 }
 
 class PollOverride {
@@ -89,7 +89,7 @@
 class PollingOverrider : public PollOverride {
  public:
   explicit PollingOverrider(bool allow_blocking)
-      : PollOverride(allow_blocking ? poll : assert_non_blocking_poll) {}
+      : PollOverride(allow_blocking ? poll : non_blocking_poll) {}
 };
 #else
 class PollingOverrider {
@@ -180,9 +180,11 @@
 
 class AsyncEnd2endTest : public ::testing::TestWithParam<bool> {
  protected:
-  AsyncEnd2endTest(): poll_override_(GetParam()) {}
+  AsyncEnd2endTest() {}
 
   void SetUp() GRPC_OVERRIDE {
+    poll_overrider_.reset(new PollingOverrider(!GetParam()));
+
     int port = grpc_pick_unused_port_or_die();
     server_address_ << "localhost:" << port;
 
@@ -202,6 +204,7 @@
     cq_->Shutdown();
     while (cq_->Next(&ignored_tag, &ignored_ok))
       ;
+    poll_overrider_.reset();
   }
 
   void ResetStub() {
@@ -250,7 +253,7 @@
   grpc::testing::EchoTestService::AsyncService service_;
   std::ostringstream server_address_;
 
-  PollingOverrider poll_override_;
+  std::unique_ptr<PollingOverrider> poll_overrider_;
 };
 
 TEST_P(AsyncEnd2endTest, SimpleRpc) {
@@ -1089,7 +1092,7 @@
     Verifier(GetParam()).Expect(7, true).Verify(cq_.get());
 
     // This is expected to fail in all cases i.e for all values of
-    // server_try_cancel. This is becasue at this point, either there are no
+    // server_try_cancel. This is because at this point, either there are no
     // more msgs from the client (because client called WritesDone) or the RPC
     // is cancelled on the server
     srv_stream.Read(&recv_request, tag(8));