diff --git a/src/p_local.h b/src/p_local.h
index a2fa00c71..a8aaaeb0d 100644
--- a/src/p_local.h
+++ b/src/p_local.h
@@ -153,7 +153,7 @@ AActor *P_SpawnMissileZAimed (AActor *source, fixed_t z, AActor *dest, const PCl
 AActor *P_SpawnPlayerMissile (AActor* source, const PClass *type);
 AActor *P_SpawnPlayerMissile (AActor *source, const PClass *type, angle_t angle);
 AActor *P_SpawnPlayerMissile (AActor *source, fixed_t x, fixed_t y, fixed_t z, const PClass *type, angle_t angle, 
-							  AActor **pLineTarget = NULL, AActor **MissileActor = NULL, bool nofreeaim = false);
+							  AActor **pLineTarget = NULL, AActor **MissileActor = NULL, bool nofreeaim = false, bool noautoaim = false);
 
 void P_CheckFakeFloorTriggers (AActor *mo, fixed_t oldz, bool oldz_has_viewheight=false);
 
diff --git a/src/p_mobj.cpp b/src/p_mobj.cpp
index 267e71bb9..901372eef 100644
--- a/src/p_mobj.cpp
+++ b/src/p_mobj.cpp
@@ -5923,7 +5923,7 @@ AActor *P_SpawnPlayerMissile (AActor *source, const PClass *type, angle_t angle)
 
 AActor *P_SpawnPlayerMissile (AActor *source, fixed_t x, fixed_t y, fixed_t z,
 							  const PClass *type, angle_t angle, AActor **pLineTarget, AActor **pMissileActor,
-							  bool nofreeaim)
+							  bool nofreeaim, bool noautoaim)
 {
 	static const int angdiff[3] = { -1<<26, 1<<26, 0 };
 	angle_t an = angle;
@@ -5936,7 +5936,7 @@ AActor *P_SpawnPlayerMissile (AActor *source, fixed_t x, fixed_t y, fixed_t z,
 	{
 		return NULL;
 	}
-	if (source->player && source->player->ReadyWeapon && (source->player->ReadyWeapon->WeaponFlags & WIF_NOAUTOAIM))
+	if (source->player && source->player->ReadyWeapon && ((source->player->ReadyWeapon->WeaponFlags & WIF_NOAUTOAIM) || noautoaim))
 	{
 		// Keep exactly the same angle and pitch as the player's own aim
 		an = angle;
diff --git a/src/thingdef/thingdef_codeptr.cpp b/src/thingdef/thingdef_codeptr.cpp
index 62a22532c..dab68867b 100644
--- a/src/thingdef/thingdef_codeptr.cpp
+++ b/src/thingdef/thingdef_codeptr.cpp
@@ -1320,6 +1320,7 @@ enum FP_Flags
 {
 	FPF_AIMATANGLE = 1,
 	FPF_TRANSFERTRANSLATION = 2,
+	FPF_NOAUTOAIM = 4,
 };
 DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_FireCustomMissile)
 {
@@ -1358,7 +1359,7 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_FireCustomMissile)
 		// Temporarily adjusts the pitch
 		fixed_t SavedPlayerPitch = self->pitch;
 		self->pitch -= pitch;
-		AActor * misl=P_SpawnPlayerMissile (self, x, y, z, ti, shootangle, &linetarget);
+		AActor * misl=P_SpawnPlayerMissile (self, x, y, z, ti, shootangle, &linetarget, NULL, false, (Flags & FPF_NOAUTOAIM) != 0);
 		self->pitch = SavedPlayerPitch;
 
 		// automatic handling of seeker missiles
diff --git a/wadsrc/static/actors/constants.txt b/wadsrc/static/actors/constants.txt
index 04ed6f1fc..b5a8b8cd4 100644
--- a/wadsrc/static/actors/constants.txt
+++ b/wadsrc/static/actors/constants.txt
@@ -188,6 +188,7 @@ const int CPF_STEALARMOR = 32;
 // Flags for A_CustomMissile
 const int FPF_AIMATANGLE = 1;
 const int FPF_TRANSFERTRANSLATION = 2;
+const int FPF_NOAUTOAIM = 4;
 
 // Flags for A_Teleport
 enum
diff --git a/wadsrc/static/actors/shared/inventory.txt b/wadsrc/static/actors/shared/inventory.txt
index 541dd37ac..13ae00936 100644
--- a/wadsrc/static/actors/shared/inventory.txt
+++ b/wadsrc/static/actors/shared/inventory.txt
@@ -10,7 +10,7 @@ ACTOR Inventory native
 	action native A_JumpIfNoAmmo(state label);
 	action native A_CustomPunch(int damage, bool norandom = false, int flags = CPF_USEAMMO, class<Actor> pufftype = "BulletPuff", float range = 0, float lifesteal = 0, int lifestealmax = 0, class<BasicArmorBonus> armorbonustype = "ArmorBonus");
 	action native A_FireBullets(float spread_xy, float spread_z, int numbullets, int damageperbullet, class<Actor> pufftype = "BulletPuff", int flags = 1, float range = 0);
-	action native A_FireCustomMissile(class<Actor> missiletype, float angle = 0, bool useammo = true, int spawnofs_xy = 0, float spawnheight = 0, bool aimatangle = false, float pitch = 0);
+	action native A_FireCustomMissile(class<Actor> missiletype, float angle = 0, bool useammo = true, int spawnofs_xy = 0, float spawnheight = 0, int flags = 0, float pitch = 0);
 	action native A_RailAttack(int damage, int spawnofs_xy = 0, int useammo = true, color color1 = "", color color2 = "", int flags = 0, float maxdiff = 0, class<Actor> pufftype = "BulletPuff", float spread_xy = 0, float spread_z = 0, float range = 0, int duration = 0, float sparsity = 1.0, float driftspeed = 1.0, class<Actor> spawnclass = "none", float spawnofs_z = 0, int spiraloffset = 270);
 	action native A_Light(int extralight);
 	action native A_Light0();