diff --git a/engine/server/sv_main.c b/engine/server/sv_main.c
index 1502029f5..9900cc031 100644
--- a/engine/server/sv_main.c
+++ b/engine/server/sv_main.c
@@ -2788,6 +2788,7 @@ void SV_InitLocal (void)
 	extern	cvar_t	sv_wateraccelerate;
 	extern	cvar_t	sv_friction;
 	extern	cvar_t	sv_waterfriction;
+	extern	cvar_t	pr_allowbutton1;
 
 	extern	cvar_t	pm_bunnyspeedcap;
 	extern	cvar_t	pm_ktjump;
@@ -2891,6 +2892,7 @@ void SV_InitLocal (void)
 	Cvar_Register (&sv_phs,	cvargroup_servercontrol);
 
 	Cvar_Register (&sv_nomsec,	cvargroup_serverphysics);
+	Cvar_Register (&pr_allowbutton1, cvargroup_servercontrol);
 
 	Cvar_Register (&pausable,	cvargroup_servercontrol);
 
diff --git a/engine/server/sv_user.c b/engine/server/sv_user.c
index 286f0689e..af98da0be 100644
--- a/engine/server/sv_user.c
+++ b/engine/server/sv_user.c
@@ -57,6 +57,7 @@ cvar_t	voteminimum	= {"voteminimum", "4"};
 cvar_t	votepercent = {"votepercent", "-1"};
 cvar_t	votetime = {"votetime", "10"};
 
+cvar_t	pr_allowbutton1 = {"pr_allowbutton1", "1", NULL, CVAR_LATCH};
 
 extern cvar_t	pm_bunnyspeedcap;
 extern cvar_t	pm_ktjump;
@@ -3449,6 +3450,8 @@ void SV_RunCmd (usercmd_t *ucmd, qboolean recurse)
 
 	sv_player->v.button0 = ucmd->buttons & 1;
 	sv_player->v.button2 = (ucmd->buttons & 2)>>1;
+	if (pr_allowbutton1.value)	//many mods use button1 - it's just a wasted field to many mods. So only work it if the cvar allows.
+		sv_player->v.button1 = (ucmd->buttons & 4) >> 2;
 	if (ucmd->impulse && SV_FiltureImpulse(ucmd->impulse, host_client->trustlevel))
 		sv_player->v.impulse = ucmd->impulse;