diff --git a/conf/options/charon.opt b/conf/options/charon.opt
index 3970012d2..04e099e12 100644
--- a/conf/options/charon.opt
+++ b/conf/options/charon.opt
@@ -100,11 +100,12 @@ charon.flush_auth_cfg = no
 charon.follow_redirects = yes
 	Whether to follow IKEv2 redirects (RFC 5685).
 
-charon.fragment_size = 0
+charon.fragment_size = 1280
 	Maximum size (complete IP datagram size in bytes) of a sent IKE fragment
-	when using proprietary IKEv1 or standardized IKEv2 fragmentation (0 for
-	address family specific	default values). If specified this limit is used
-	for both IPv4 and IPv6.
+	when using proprietary IKEv1 or standardized IKEv2 fragmentation, defaults
+	to 1280 (use 0 for address family specific default values, which uses a
+	lower value for IPv4).  If specified this limit is used for both IPv4 and
+	IPv6.
 
 charon.group
 	Name of the group the daemon changes to after startup.
diff --git a/src/libcharon/sa/ike_sa.c b/src/libcharon/sa/ike_sa.c
index 239e260b1..ceeafcbb8 100644
--- a/src/libcharon/sa/ike_sa.c
+++ b/src/libcharon/sa/ike_sa.c
@@ -2979,7 +2979,7 @@ ike_sa_t * ike_sa_create(ike_sa_id_t *ike_sa_id, bool initiator,
 		.flush_auth_cfg = lib->settings->get_bool(lib->settings,
 								"%s.flush_auth_cfg", FALSE, lib->ns),
 		.fragment_size = lib->settings->get_int(lib->settings,
-								"%s.fragment_size", 0, lib->ns),
+								"%s.fragment_size", 1280, lib->ns),
 		.follow_redirects = lib->settings->get_bool(lib->settings,
 								"%s.follow_redirects", TRUE, lib->ns),
 	);