diff --git a/engine/common/mod_local.h b/engine/common/mod_local.h
index cd2cc234..461b6917 100644
--- a/engine/common/mod_local.h
+++ b/engine/common/mod_local.h
@@ -155,7 +155,6 @@ void Mod_LoadCacheFile( const char *path, struct cache_user_s *cu );
 void *Mod_AliasExtradata( model_t *mod );
 void *Mod_StudioExtradata( model_t *mod );
 model_t *Mod_FindName( const char *name, qboolean trackCRC );
-model_t *Mod_LoadModel( model_t *mod, qboolean crash );
 model_t *Mod_ForName( const char *name, qboolean crash, qboolean trackCRC );
 qboolean Mod_ValidateCRC( const char *name, uint32_t crc );
 void Mod_NeedCRC( const char *name, qboolean needCRC );
diff --git a/engine/common/model.c b/engine/common/model.c
index d8d65ced..97b78e29 100644
--- a/engine/common/model.c
+++ b/engine/common/model.c
@@ -292,7 +292,7 @@ Mod_LoadModel
 Loads a model into the cache
 ==================
 */
-model_t *Mod_LoadModel( model_t *mod, qboolean crash )
+static model_t *Mod_LoadModel( model_t *mod, qboolean crash )
 {
 	char		tempname[MAX_QPATH];
 	fs_offset_t		length = 0;
diff --git a/engine/common/net_chan.c b/engine/common/net_chan.c
index 7e2a27ac..f8606d9d 100644
--- a/engine/common/net_chan.c
+++ b/engine/common/net_chan.c
@@ -94,6 +94,7 @@ CVAR_DEFINE_AUTO( net_showpackets, "0", FCVAR_PRIVILEGED, "show network packets"
 static CVAR_DEFINE_AUTO( net_chokeloop, "0", 0, "apply bandwidth choke to loopback packets" );
 static CVAR_DEFINE_AUTO( net_showdrop, "0", 0, "show packets that are dropped" );
 static CVAR_DEFINE_AUTO( net_qport, "0", FCVAR_READ_ONLY, "current quake netport" );
+static CVAR_DEFINE_AUTO( net_sequence_window, "256", 0, "reject sequenced packets that jump more than this many sequences ahead (anti-spoofing; 0 disables)" );
 CVAR_DEFINE_AUTO( net_send_debug, "0", FCVAR_PRIVILEGED, "enable debugging output for outgoing messages" );
 CVAR_DEFINE_AUTO( net_recv_debug, "0", FCVAR_PRIVILEGED, "enable debugging output for incoming messages" );
 
@@ -173,6 +174,7 @@ void Netchan_Init( void )
 	Cvar_RegisterVariable( &net_chokeloop );
 	Cvar_RegisterVariable( &net_showdrop );
 	Cvar_RegisterVariable( &net_qport );
+	Cvar_RegisterVariable( &net_sequence_window );
 	Cvar_RegisterVariable( &net_send_debug );
 	Cvar_RegisterVariable( &net_recv_debug );
 	Cvar_FullSet( net_qport.name, buf, net_qport.flags );
@@ -1856,6 +1858,16 @@ qboolean Netchan_Process( netchan_t *chan, sizebuf_t *msg )
 		return false;
 	}
 
+	// reject packets that leap too far ahead of the expected sequence
+	if( net_sequence_window.value > 0 && sequence > chan->incoming_sequence + (uint)net_sequence_window.value )
+	{
+		Con_Printf( S_WARN "%s: %s: sequence %u jumps %u ahead of expected %i (window %i), dropping\n",
+			__func__, NET_AdrToString( chan->remote_address ),
+			sequence, sequence - chan->incoming_sequence,
+			chan->incoming_sequence, (int)net_sequence_window.value );
+		return false;
+	}
+
 	// dropped packets don't keep the message from being used
 	net_drop = sequence - ( chan->incoming_sequence + 1 );
 	if( net_drop > 0 && net_showdrop.value )