diff --git a/lib/http_proxy.c b/lib/http_proxy.c
index 7fde11dbb..a67328647 100644
--- a/lib/http_proxy.c
+++ b/lib/http_proxy.c
@@ -515,33 +515,34 @@ CURLcode Curl_proxyCONNECT(struct connectdata *conn,
         }
         else if(checkprefix("Content-Length:", line_start)) {
           if(k->httpcode/100 == 2) {
-            /* A server MUST NOT send any Transfer-Encoding or
-               Content-Length header fields in a 2xx (Successful)
-               response to CONNECT. (RFC 7231 section 4.3.6) */
-            failf(data, "Content-Length: in %03d response",
+            /* A client MUST ignore any Content-Length or Transfer-Encoding
+               header fields received in a successful response to CONNECT.
+               "Successful" described as: 2xx (Successful). RFC 7231 4.3.6 */
+            infof(data, "Ignoring Content-Length in CONNECT %03d response\n",
                   k->httpcode);
-            return CURLE_RECV_ERROR;
           }
-
-          cl = curlx_strtoofft(line_start +
-                               strlen("Content-Length:"), NULL, 10);
+          else {
+            cl = curlx_strtoofft(line_start +
+                                 strlen("Content-Length:"), NULL, 10);
+          }
         }
         else if(Curl_compareheader(line_start, "Connection:", "close"))
           closeConnection = TRUE;
-        else if(Curl_compareheader(line_start,
-                                   "Transfer-Encoding:",
-                                   "chunked")) {
+        else if(checkprefix("Transfer-Encoding:", line_start)) {
           if(k->httpcode/100 == 2) {
-            /* A server MUST NOT send any Transfer-Encoding or
-               Content-Length header fields in a 2xx (Successful)
-               response to CONNECT. (RFC 7231 section 4.3.6) */
-            failf(data, "Transfer-Encoding: in %03d response", k->httpcode);
-            return CURLE_RECV_ERROR;
+            /* A client MUST ignore any Content-Length or Transfer-Encoding
+               header fields received in a successful response to CONNECT.
+               "Successful" described as: 2xx (Successful). RFC 7231 4.3.6 */
+            infof(data, "Ignoring Transfer-Encoding in "
+                  "CONNECT %03d response\n", k->httpcode);
+          }
+          else if(Curl_compareheader(line_start,
+                                     "Transfer-Encoding:", "chunked")) {
+            infof(data, "CONNECT responded chunked\n");
+            chunked_encoding = TRUE;
+            /* init our chunky engine */
+            Curl_httpchunk_init(conn);
           }
-          infof(data, "CONNECT responded chunked\n");
-          chunked_encoding = TRUE;
-          /* init our chunky engine */
-          Curl_httpchunk_init(conn);
         }
         else if(Curl_compareheader(line_start, "Proxy-Connection:", "close"))
           closeConnection = TRUE;
diff --git a/tests/data/Makefile.inc b/tests/data/Makefile.inc
index c51cc3595..a115ab69d 100644
--- a/tests/data/Makefile.inc
+++ b/tests/data/Makefile.inc
@@ -131,7 +131,7 @@ test1244 test1245 test1246 test1247 test1248 test1249 test1250 test1251 \
 test1252 test1253 test1254 test1255 test1256 test1257 test1258 test1259 \
 test1260 \
 \
-test1280 test1281 test1282 test1283 test1284 test1285 test1286 \
+test1280 test1281 test1282 test1283 test1284 test1285 test1286 test1287 \
 \
 test1300 test1301 test1302 test1303 test1304 test1305 test1306 test1307 \
 test1308 test1309 test1310 test1311 test1312 test1313 test1314 test1315 \
diff --git a/tests/data/test1287 b/tests/data/test1287
new file mode 100644
index 000000000..83a2cd040
--- /dev/null
+++ b/tests/data/test1287
@@ -0,0 +1,90 @@
+<testcase>
+<info>
+<keywords>
+HTTP
+HTTP GET
+HTTP CONNECT
+proxytunnel
+</keywords>
+</info>
+#
+# Server-side
+<reply>
+<data>
+HTTP/1.1 200 OK
+Date: Thu, 09 Nov 2010 14:49:00 GMT
+Server: test-server/fake swsclose
+Content-Type: text/html
+Funny-head: yesyes
+Content-Length: 9
+
+contents
+</data>
+
+# The purpose of this test is to make sure curl ignores headers
+# Content-Length and Transfer-Encoding in a successful CONNECT 2xx reply.
+<connect>
+HTTP/1.1 200 Mighty fine indeed
+Content-Length: 123
+Transfer-Encoding: chunked
+
+</connect>
+
+<datacheck>
+HTTP/1.1 200 Mighty fine indeed
+Content-Length: 123
+Transfer-Encoding: chunked
+
+HTTP/1.1 200 OK
+Date: Thu, 09 Nov 2010 14:49:00 GMT
+Server: test-server/fake swsclose
+Content-Type: text/html
+Funny-head: yesyes
+Content-Length: 9
+
+contents
+</datacheck>
+</reply>
+
+#
+# Client-side
+<client>
+<server>
+http
+http-proxy
+</server>
+<name>
+HTTP over proxy-tunnel ignore TE and CL in CONNECT 2xx responses
+</name>
+<command>
+-v --proxytunnel -x %HOSTIP:%PROXYPORT http://test.1287:%HTTPPORT/we/want/that/page/1287
+</command>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+<strip>
+^User-Agent:.*
+</strip>
+<proxy>
+CONNECT test.1287:%HTTPPORT HTTP/1.1
+Host: test.1287:%HTTPPORT
+Proxy-Connection: Keep-Alive
+
+</proxy>
+<protocol>
+GET /we/want/that/page/1287 HTTP/1.1
+Host: test.1287:%HTTPPORT
+Accept: */*
+
+</protocol>
+<file name="log/stderr1287" mode="text">
+* Ignoring Content-Length in CONNECT 200 response
+* Ignoring Transfer-Encoding in CONNECT 200 response
+</file>
+<stripfile>
+s/^.*(?=\* Ignoring (?:Content-Length|Transfer-Encoding) )// or $_ = ''
+</stripfile>
+</verify>
+</testcase>