diff --git a/src/p_pspr.cpp b/src/p_pspr.cpp
index 606acdb26..8b8c5bcdc 100644
--- a/src/p_pspr.cpp
+++ b/src/p_pspr.cpp
@@ -660,10 +660,16 @@ DEFINE_ACTION_FUNCTION(AInventory, A_Raise)
 //
 // A_GunFlash
 //
+enum GF_Flags
+{
+	GFF_NOEXTCHANGE = 1,
+};
+
 DEFINE_ACTION_FUNCTION_PARAMS(AInventory, A_GunFlash)
 {
-	ACTION_PARAM_START(1)
+	ACTION_PARAM_START(2)
 	ACTION_PARAM_STATE(flash, 0);
+	ACTION_PARAM_INT(Flags, 1);
 
 	player_t *player = self->player;
 
@@ -671,7 +677,7 @@ DEFINE_ACTION_FUNCTION_PARAMS(AInventory, A_GunFlash)
 	{
 		return;
 	}
-	player->mo->PlayAttacking2 ();
+	if(!(Flags & GFF_NOEXTCHANGE)) player->mo->PlayAttacking2 ();
 
 	if (flash == NULL)
 	{
diff --git a/wadsrc/static/actors/constants.txt b/wadsrc/static/actors/constants.txt
index c5159bbf7..7a65c3d9d 100644
--- a/wadsrc/static/actors/constants.txt
+++ b/wadsrc/static/actors/constants.txt
@@ -19,6 +19,9 @@ const int CBAF_NORANDOM = 2;
 const int CBAF_EXPLICITANGLE = 4;
 const int CBAF_NOPITCH = 8;
 
+// Flags for A_GunFlash
+const int GFF_NOEXTCHANGE = 1;
+
 // Flags for A_FireBullets
 const int FBF_USEAMMO = 1;
 const int FBF_NORANDOM = 2;
diff --git a/wadsrc/static/actors/shared/inventory.txt b/wadsrc/static/actors/shared/inventory.txt
index 49b6b39a2..3088ffff0 100644
--- a/wadsrc/static/actors/shared/inventory.txt
+++ b/wadsrc/static/actors/shared/inventory.txt
@@ -40,7 +40,7 @@ ACTOR Inventory native
 	action native A_ReFire(state flash = "");
 	action native A_ClearReFire();
 	action native A_CheckReload();
-	action native A_GunFlash(state flash = "");
+	action native A_GunFlash(state flash = "", int flags = 0);
 	action native A_Saw(sound fullsound = "weapons/sawfull", sound hitsound = "weapons/sawhit", int damage = 2, class<Actor> pufftype = "BulletPuff", int flags = 0, float range = 0, float spread_xy = 2.8125, float spread_z = 0, float lifesteal = 0);
 	action native A_CheckForReload(int counter, state label, bool dontincrement = false);
 	action native A_ResetReloadCounter();