diff --git a/src/net/spdy/spdy_proxy_client_socket.cc b/src/net/spdy/spdy_proxy_client_socket.cc
index 1c21ca0586..9ee770ee55 100644
--- a/src/net/spdy/spdy_proxy_client_socket.cc
+++ b/src/net/spdy/spdy_proxy_client_socket.cc
@@ -321,6 +321,11 @@ void SpdyProxyClientSocket::OnIOComplete(int result) {
   DCHECK_NE(STATE_DISCONNECTED, next_state_);
   int rv = DoLoop(result);
   if (rv != ERR_IO_PENDING) {
+    if (use_fastopen_ && read_headers_pending_ == false) {
+      if (rv < 0)
+        next_state_ = STATE_DISCONNECTED;
+      if (!read_callback_ || rv == OK) return;
+    }
     std::move(read_callback_).Run(rv);
   }
 }
@@ -394,20 +399,6 @@ int SpdyProxyClientSocket::DoLoop(int last_io_result) {
       case STATE_PROCESS_RESPONSE_CODE:
         DCHECK_EQ(OK, rv);
         rv = DoProcessResponseCode();
-        if (use_fastopen_ && read_headers_pending_) {
-          read_headers_pending_ = false;
-          if (rv < 0) {
-            // read_callback_ cannot be called.
-            if (!read_callback_)
-              rv = ERR_IO_PENDING;
-            // read_callback_ will be called with this error and be reset.
-            // Further data after that will be ignored.
-            next_state_ = STATE_DISCONNECTED;
-          } else {
-            // Does not call read_callback_ from here if headers are OK.
-            rv = ERR_IO_PENDING;
-          }
-        }
         break;
       default:
         NOTREACHED() << "bad state";
@@ -554,12 +545,6 @@ int SpdyProxyClientSocket::DoReadReplyComplete(int result) {
   if (result < 0)
     return result;
 
-  // SpdyHeadersToHttpResponse() may have failed to convert the response
-  // headers (e.g. duplicate location values), in which case
-  // response_.headers is null and must not be dereferenced.
-  if (!response_.headers)
-    return ERR_TUNNEL_CONNECTION_FAILED;
-
   // Require the "HTTP/1.x" status line for SSL CONNECT.
   if (response_.headers->GetHttpVersion() < HttpVersion(1, 0))
     return ERR_TUNNEL_CONNECTION_FAILED;
@@ -639,6 +624,7 @@ void SpdyProxyClientSocket::OnEarlyHintsReceived(
 void SpdyProxyClientSocket::OnHeadersReceived(
     const quiche::HttpHeaderBlock& response_headers) {
   if (use_fastopen_ && read_headers_pending_ && next_state_ == STATE_OPEN) {
+    read_headers_pending_ = false;
     next_state_ = STATE_READ_REPLY_COMPLETE;
   }
 
@@ -652,7 +638,7 @@ void SpdyProxyClientSocket::OnHeadersReceived(
   const int rv = SpdyHeadersToHttpResponse(response_headers, &response_);
   DCHECK_NE(rv, ERR_INCOMPLETE_HTTP2_HEADERS);
 
-  OnIOComplete(OK);
+  OnIOComplete(rv);
 }
 
 // Called when data is received or on EOF (if `buffer is nullptr).
diff --git a/src/net/spdy/spdy_proxy_client_socket.h b/src/net/spdy/spdy_proxy_client_socket.h
index cd3c408529..90ffed4274 100644
--- a/src/net/spdy/spdy_proxy_client_socket.h
+++ b/src/net/spdy/spdy_proxy_client_socket.h
@@ -202,7 +202,7 @@ class NET_EXPORT_PRIVATE SpdyProxyClientSocket : public ProxyClientSocket,
 
   bool use_fastopen_ = false;
   std::optional<size_t> preamble_index_;
-  bool read_headers_pending_ = false;
+  std::optional<bool> read_headers_pending_;
 
   const NetLogWithSource net_log_;
   const NetLogSource source_dependency_;