diff --git a/docs/libcurl/libcurl-errors.3 b/docs/libcurl/libcurl-errors.3
index 64b3454eb..596d0e0b1 100644
--- a/docs/libcurl/libcurl-errors.3
+++ b/docs/libcurl/libcurl-errors.3
@@ -210,6 +210,9 @@ An easy handle was not good/valid.
 You are doomed.
 .IP "CURLM_INTERNAL_ERROR (4)"
 This can only be returned if libcurl bugs. Please report it to us!
+.IP "CURLM_BAD_SOCKET (5)"
+The passed-in socket is not a valid one that libcurl already knows about.
+(Added in 7.16.0)
 .SH "CURLSHcode"
 The "share" interface will return a CURLSHcode to indicate when an error has
 occurred.  Also consider \fIcurl_share_strerror(3)\fP.