diff --git a/CHANGES b/CHANGES
index c195f375d4..61a6d3d859 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+6213.	[bug]		Mark a primary server as temporarily unreachable if the
+			TCP connection attempt times out. [GL #4215]
+
 6212.	[bug]		Don't process detach and close netmgr events when
 			the netmgr has been paused. [GL #4200]
 
diff --git a/lib/dns/xfrin.c b/lib/dns/xfrin.c
index b481368129..53572774b3 100644
--- a/lib/dns/xfrin.c
+++ b/lib/dns/xfrin.c
@@ -1336,9 +1336,11 @@ failure:
 	case ISC_R_NETUNREACH:
 	case ISC_R_HOSTUNREACH:
 	case ISC_R_CONNREFUSED:
+	case ISC_R_TIMEDOUT:
 		/*
-		 * Add the server to unreachable primaries table only if
-		 * the server has a permanent networking error.
+		 * Add the server to unreachable primaries table if
+		 * the server has a permanent networking error or
+		 * the connection attempt as timed out.
 		 */
 		zmgr = dns_zone_getmgr(xfr->zone);
 		if (zmgr != NULL) {