diff --git a/engine/client/cl_main.c b/engine/client/cl_main.c
index fe237168..8f6e439e 100644
--- a/engine/client/cl_main.c
+++ b/engine/client/cl_main.c
@@ -709,6 +709,7 @@ void CL_WritePacket( void )
 
 	CL_ComputePacketLoss ();
 
+	memset( data, 0, sizeof( data ));
 	MSG_Init( &buf, "ClientData", data, sizeof( data ));
 
 	// Determine number of backup commands to send along
diff --git a/engine/common/net_chan.c b/engine/common/net_chan.c
index ba000172..934cf007 100644
--- a/engine/common/net_chan.c
+++ b/engine/common/net_chan.c
@@ -1589,6 +1589,7 @@ void Netchan_TransmitBits( netchan_t *chan, int length, byte *data )
 		}
 	}
 
+	memset( send_buf, 0, sizeof( send_buf ));
 	MSG_Init( &send, "NetSend", send_buf, sizeof( send_buf ));
 
 	// prepare the packet header
diff --git a/engine/server/sv_client.c b/engine/server/sv_client.c
index 26bb4870..0894091b 100644
--- a/engine/server/sv_client.c
+++ b/engine/server/sv_client.c
@@ -1632,6 +1632,7 @@ static qboolean SV_New_f( sv_client_t *cl )
 	sizebuf_t		msg;
 	int		i;
 
+	memset( msg_buf, 0, sizeof( msg_buf ));
 	MSG_Init( &msg, "New", msg_buf, sizeof( msg_buf ));
 
 	if( cl->state != cs_connected )
@@ -1982,6 +1983,7 @@ static qboolean SV_SendRes_f( sv_client_t *cl )
 	if( cl->state != cs_connected )
 		return false;
 
+	memset( buffer, 0, sizeof( buffer ));
 	MSG_Init( &msg, "SendResources", buffer, sizeof( buffer ));
 
 	if( svs.maxclients > 1 && FBitSet( cl->flags, FCL_SEND_RESOURCES ))
diff --git a/engine/server/sv_frame.c b/engine/server/sv_frame.c
index 55c871f5..c1452a24 100644
--- a/engine/server/sv_frame.c
+++ b/engine/server/sv_frame.c
@@ -711,6 +711,7 @@ void SV_SendClientDatagram( sv_client_t *cl )
 	byte	msg_buf[MAX_DATAGRAM];
 	sizebuf_t	msg;
 
+	memset( msg_buf, 0, sizeof( msg_buf ));
 	MSG_Init( &msg, "Datagram", msg_buf, sizeof( msg_buf ));
 
 	// always send servertime at new frame