diff --git a/src/thingdef/thingdef_codeptr.cpp b/src/thingdef/thingdef_codeptr.cpp
index 171913e78..3770001c9 100644
--- a/src/thingdef/thingdef_codeptr.cpp
+++ b/src/thingdef/thingdef_codeptr.cpp
@@ -2633,6 +2633,15 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_SpawnDebris)
 // A_SpawnParticle
 //
 //===========================================================================
+enum SPFflag
+{
+	SPF_FULLBRIGHT =	1,
+	SPF_RELPOS =		1 << 1,
+	SPF_RELVEL =		1 << 2,
+	SPF_RELACCEL =		1 << 3,
+	SPF_RELANG =		1 << 4,
+};
+
 DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_SpawnParticle)
 {
 	ACTION_PARAM_START(15);
@@ -2644,13 +2653,14 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_SpawnParticle)
 	ACTION_PARAM_FIXED(zvel, 5);
 	ACTION_PARAM_COLOR(color, 6);
 	ACTION_PARAM_INT(lifetime, 7);
-	ACTION_PARAM_BOOL(fullbright, 8);
+	ACTION_PARAM_INT(flags, 8);
 	ACTION_PARAM_FIXED(startalphaf, 9);
 	ACTION_PARAM_INT(size, 10);
 	ACTION_PARAM_FIXED(fadestepf, 11);
 	ACTION_PARAM_FIXED(accelx, 12);
 	ACTION_PARAM_FIXED(accely, 13);
 	ACTION_PARAM_FIXED(accelz, 14);
+	ACTION_PARAM_ANGLE(angle, 15);
 
 	BYTE startalpha = (BYTE)Scale(clamp(startalphaf, 0, FRACUNIT), 255, FRACUNIT);
 	int fadestep = fadestepf < 0? -1 : Scale(clamp(fadestepf, 0, FRACUNIT), 255, FRACUNIT);
@@ -2659,8 +2669,31 @@ DEFINE_ACTION_FUNCTION_PARAMS(AActor, A_SpawnParticle)
 
 	if (lifetime != 0)
 	{
-		fixedvec3 pos = self->Vec3Offset(xoff, yoff, zoff);
-		P_SpawnParticle(pos.x, pos.y, pos.z, xvel, yvel, zvel, color, fullbright, startalpha, lifetime, size, fadestep, accelx, accely, accelz);
+		const angle_t ang = (angle + ((flags & SPF_RELANG) ? self->angle : 0)) >> ANGLETOFINESHIFT;
+		fixedvec3 pos;
+		//[MC] Code ripped right out of A_SpawnItemEx.
+		if (flags & SPF_RELPOS)
+		{
+			// in relative mode negative y values mean 'left' and positive ones mean 'right'
+			// This is the inverse orientation of the absolute mode!
+			const fixed_t xof1 = xoff;
+			xoff = FixedMul(xof1, finecosine[ang]) + FixedMul(yoff, finesine[ang]);
+			yoff = FixedMul(xof1, finesine[ang]) - FixedMul(yoff, finecosine[ang]);
+		}
+		if (flags & SPF_RELVEL)
+		{
+			const fixed_t newxvel = FixedMul(xvel, finecosine[ang]) + FixedMul(yvel, finesine[ang]);
+			yvel = FixedMul(xvel, finesine[ang]) - FixedMul(yvel, finecosine[ang]);
+			xvel = newxvel;
+		}
+		if (flags & SPF_RELACCEL)
+		{
+			fixed_t newaccelx = FixedMul(accelx, finecosine[ang]) + FixedMul(accely, finesine[ang]);
+			accely = FixedMul(accelx, finesine[ang]) - FixedMul(accely, finecosine[ang]);
+			accelx = newaccelx;
+		}
+		pos = self->Vec3Offset(xoff, yoff, zoff);
+		P_SpawnParticle(pos.x, pos.y, pos.z, xvel, yvel, zvel, color, !!(flags & SPF_FULLBRIGHT), startalpha, lifetime, size, fadestep, accelx, accely, accelz);
 	}
 }
 
diff --git a/wadsrc/static/actors/actor.txt b/wadsrc/static/actors/actor.txt
index 14925eb5a..07dd0871b 100644
--- a/wadsrc/static/actors/actor.txt
+++ b/wadsrc/static/actors/actor.txt
@@ -234,7 +234,7 @@ ACTOR Actor native //: Thinker
 	action native A_SetScale(float scalex, float scaley = 0, int ptr = AAPTR_DEFAULT);
 	action native A_SetMass(int mass);
 	action native A_SpawnDebris(class<Actor> spawntype, bool transfer_translation = false, float mult_h = 1, float mult_v = 1);
-	action native A_SpawnParticle(float xoff, float yoff, float zoff, float velx, float vely, float velz, color color1, int lifetime, bool fullbright = false, float startalpha = 1, int size = 1, float fadestep = -1, float accelx = 0.0, float accely = 0.0, float accelz = 0.0);
+	action native A_SpawnParticle(float xoff, float yoff, float zoff, float velx, float vely, float velz, color color1, int lifetime, int flags = 0, float startalpha = 1, int size = 1, float fadestep = -1, float accelx = 0.0, float accely = 0.0, float accelz = 0.0, float angle = 0);
 	action native A_CheckSight(state label);
 	action native A_ExtChase(bool usemelee, bool usemissile, bool playactive = true, bool nightmarefast = false);
 	action native A_DropInventory(class<Inventory> itemtype);
diff --git a/wadsrc/static/actors/constants.txt b/wadsrc/static/actors/constants.txt
index a88290451..b2d641b69 100644
--- a/wadsrc/static/actors/constants.txt
+++ b/wadsrc/static/actors/constants.txt
@@ -511,6 +511,17 @@ enum
 	CBF_SETONPTR		= 1 << 4,	//Sets the pointer change on the actor doing the checking instead of self.
 };
 
+enum
+{
+	SPF_FULLBRIGHT =	1,
+	SPF_RELPOS =		1 << 1,
+	SPF_RELVEL =		1 << 2,
+	SPF_RELACCEL =		1 << 3,
+	SPF_RELANG =		1 << 4,
+
+	SPF_RELATIVE =	SPF_RELPOS|SPF_RELVEL|SPF_RELACCEL|SPF_RELANG
+};
+
 // This is only here to provide one global variable for testing.
 native int testglobalvar;