diff --git a/src/net/spdy/spdy_proxy_client_socket.cc b/src/net/spdy/spdy_proxy_client_socket.cc
index 62877bba9f..3cfa333731 100644
--- a/src/net/spdy/spdy_proxy_client_socket.cc
+++ b/src/net/spdy/spdy_proxy_client_socket.cc
@@ -277,10 +277,11 @@ int SpdyProxyClientSocket::GetLocalAddress(IPEndPoint* address) const {
 }
 
 void SpdyProxyClientSocket::RunWriteCallback(int result) {
-  CHECK(write_callback_);
-
   base::WeakPtr<SpdyProxyClientSocket> weak_ptr = weak_factory_.GetWeakPtr();
-  std::move(write_callback_).Run(result);
+  // `write_callback_` might be consumed by OnClose().
+  if (write_callback_) {
+    std::move(write_callback_).Run(result);
+  }
   if (!weak_ptr) {
     // `this` was already destroyed while running `write_callback_`. Must
     // return immediately without touching any field member.