diff --git a/engine/common/net_chan.c b/engine/common/net_chan.c
index f6f0d275..cbf26cbd 100644
--- a/engine/common/net_chan.c
+++ b/engine/common/net_chan.c
@@ -1504,7 +1504,7 @@ transmition / retransmition of the reliable messages.
 A 0 length will still generate a packet and deal with the reliable messages.
 ================
 */
-void Netchan_TransmitBits( netchan_t *chan, int length, byte *data )
+void Netchan_TransmitBits( netchan_t *chan, int length, const byte *data )
 {
 	byte	send_buf[NET_MAX_MESSAGE];
 	qboolean	send_reliable_fragment;
diff --git a/engine/common/netchan.h b/engine/common/netchan.h
index 22e01770..5912be3f 100644
--- a/engine/common/netchan.h
+++ b/engine/common/netchan.h
@@ -305,7 +305,7 @@ qboolean Netchan_CopyNormalFragments( netchan_t *chan, sizebuf_t *msg, size_t *l
 qboolean Netchan_CopyFileFragments( netchan_t *chan, sizebuf_t *msg );
 void Netchan_CreateFragments( netchan_t *chan, sizebuf_t *msg );
 int Netchan_CreateFileFragments( netchan_t *chan, const char *filename );
-void Netchan_TransmitBits( netchan_t *chan, int lengthInBits, byte *data );
+void Netchan_TransmitBits( netchan_t *chan, int lengthInBits, const byte *data );
 void Netchan_OutOfBand( int net_socket, netadr_t adr, int length, byte *data );
 void Netchan_OutOfBandPrint( int net_socket, netadr_t adr, const char *format, ... ) _format( 3 );
 qboolean Netchan_Process( netchan_t *chan, sizebuf_t *msg );