diff --git a/docs/libcurl/opts/CURLOPT_PROXY.3 b/docs/libcurl/opts/CURLOPT_PROXY.3
index 3ebcc61458..22ec86d0c9 100644
--- a/docs/libcurl/opts/CURLOPT_PROXY.3
+++ b/docs/libcurl/opts/CURLOPT_PROXY.3
@@ -118,6 +118,9 @@ Since 7.21.7 the proxy string supports the socks protocols as "schemes".
 
 Since 7.50.2, unsupported schemes in proxy strings cause libcurl to return
 error.
+
+curl built to use NSS cannot connect to a HTTPS server over a unix domain
+socket.
 .SH RETURN VALUE
 Returns CURLE_OK if proxies are supported, CURLE_UNKNOWN_OPTION if not, or
 CURLE_OUT_OF_MEMORY if there was insufficient heap space.
diff --git a/tests/data/test1470 b/tests/data/test1470
index dec99543fb..7807a3dce8 100644
--- a/tests/data/test1470
+++ b/tests/data/test1470
@@ -34,6 +34,7 @@ Funny-head: yesyes
 <features>
 proxy
 unix-sockets
+!NSS
 </features>
 <server>
 https