diff --git a/src/lua_mobjlib.c b/src/lua_mobjlib.c
index eab532d9e..6d826e3bb 100644
--- a/src/lua_mobjlib.c
+++ b/src/lua_mobjlib.c
@@ -32,6 +32,8 @@ enum mobj_e {
 	mobj_angle,
 	mobj_pitch,
 	mobj_roll,
+	mobj_slopepitch,
+	mobj_sloperoll,
 	mobj_rollangle,
 	mobj_sprite,
 	mobj_frame,
@@ -117,6 +119,8 @@ static const char *const mobj_opt[] = {
 	"angle",
 	"pitch",
 	"roll",
+	"slopepitch",
+	"sloperoll",
 	"rollangle",
 	"sprite",
 	"frame",
diff --git a/src/p_mobj.c b/src/p_mobj.c
index dc2c82439..f533d63ca 100644
--- a/src/p_mobj.c
+++ b/src/p_mobj.c
@@ -1290,12 +1290,12 @@ void P_SetPitchRollFromSlope(mobj_t *mo, pslope_t *slope)
 		fixed_t tempy = slope->normal.y;
 		fixed_t tempx = slope->normal.x;
 
-		mo->pitch = R_PointToAngle2(0, 0, FixedSqrt(FixedMul(tempy, tempy) + FixedMul(tempz, tempz)), tempx);
-		mo->roll = R_PointToAngle2(0, 0, tempz, tempy);
+		mo->slopepitch = R_PointToAngle2(0, 0, FixedSqrt(FixedMul(tempy, tempy) + FixedMul(tempz, tempz)), tempx);
+		mo->sloperoll = R_PointToAngle2(0, 0, tempz, tempy);
 	}
 	else
 	{
-		mo->pitch = mo->roll = 0;
+		mo->slopepitch = mo->sloperoll = 0;
 	}
 }
 
diff --git a/src/p_mobj.h b/src/p_mobj.h
index cdd0ba610..58477770c 100644
--- a/src/p_mobj.h
+++ b/src/p_mobj.h
@@ -294,6 +294,7 @@ struct mobj_t
 
 	// More drawing info: to determine current sprite.
 	angle_t angle, pitch, roll; // orientation
+	angle_t slopepitch, sloperoll;
 	angle_t old_angle, old_pitch, old_roll; // orientation interpolation
 	angle_t old_angle2, old_pitch2, old_roll2;
 	angle_t rollangle;
diff --git a/src/p_saveg.c b/src/p_saveg.c
index c5b7d7feb..1b297244b 100644
--- a/src/p_saveg.c
+++ b/src/p_saveg.c
@@ -3735,6 +3735,10 @@ static thinker_t* LoadMobjThinker(savebuffer_t *save, actionf_p1 thinker)
 		mobj->terrain = NULL;
 	}
 
+	// Reset some non-synch values
+	mobj->sloperoll = 0;
+	mobj->slopepitch = 0;
+
 	// set sprev, snext, bprev, bnext, subsector
 	P_SetThingPosition(mobj);
 
diff --git a/src/p_user.c b/src/p_user.c
index f995b863d..0f2c785b7 100644
--- a/src/p_user.c
+++ b/src/p_user.c
@@ -4105,6 +4105,21 @@ Quaketilt (player_t *player)
 	return moma;
 }
 
+static angle_t P_GetCameraPitchRollAngle(mobj_t *mobj, player_t *viewPlayer)
+{
+	angle_t viewingAngle = R_PointToAnglePlayer(viewPlayer, mobj->x, mobj->y);
+
+	fixed_t pitchMul = -FINESINE(viewingAngle >> ANGLETOFINESHIFT);
+	fixed_t rollMul = FINECOSINE(viewingAngle >> ANGLETOFINESHIFT);
+
+	angle_t sloperolll = mobj->slopepitch;
+	angle_t slopepitch = mobj->sloperoll;
+
+	angle_t rollOrPitch = FixedMul(mobj->pitch + sloperolll, pitchMul) + FixedMul(mobj->roll + slopepitch, rollMul);
+
+	return rollOrPitch;
+}
+
 static void
 DoABarrelRoll (player_t *player)
 {
@@ -4129,7 +4144,7 @@ DoABarrelRoll (player_t *player)
 		return;
 	}
 
-	slope = InvAngle(R_GetPitchRollAngle(player->mo, player));
+	slope = InvAngle(P_GetCameraPitchRollAngle(player->mo, player));
 
 	if (AbsAngle(slope) < ANGLE_11hh)
 	{
diff --git a/src/r_main.cpp b/src/r_main.cpp
index 02577f964..f80181fc4 100644
--- a/src/r_main.cpp
+++ b/src/r_main.cpp
@@ -193,6 +193,8 @@ consvar_t cv_maxportals = CVAR_INIT ("maxportals", "2", CV_SAVE, maxportals_cons
 
 consvar_t cv_renderstats = CVAR_INIT ("renderstats", "Off", 0, CV_OnOff, NULL);
 
+consvar_t cv_sloperoll = CVAR_INIT ("spritesloperoll", "On", CV_SAVE, CV_OnOff, NULL);
+
 void SplitScreen_OnChange(void)
 {
 	UINT8 i;
@@ -1826,6 +1828,7 @@ void R_RegisterEngineStuff(void)
 	CV_RegisterVar(&cv_tilting);
 	CV_RegisterVar(&cv_actionmovie);
 	CV_RegisterVar(&cv_windowquake);
+	CV_RegisterVar(&cv_sloperoll);
 
 	CV_RegisterVar(&cv_showhud);
 	CV_RegisterVar(&cv_translucenthud);
diff --git a/src/r_main.h b/src/r_main.h
index fbf3484f2..762095bff 100644
--- a/src/r_main.h
+++ b/src/r_main.h
@@ -156,6 +156,8 @@ extern consvar_t cv_skybox;
 extern consvar_t cv_tailspickup;
 extern consvar_t cv_debugfinishline;
 
+extern consvar_t cv_sloperoll;
+
 // debugging
 
 typedef enum {
diff --git a/src/r_patchrotation.c b/src/r_patchrotation.c
index 2051d5ca0..7ecfe3ee7 100644
--- a/src/r_patchrotation.c
+++ b/src/r_patchrotation.c
@@ -28,7 +28,16 @@ angle_t R_GetPitchRollAngle(mobj_t *mobj, player_t *viewPlayer)
 	fixed_t pitchMul = -FINESINE(viewingAngle >> ANGLETOFINESHIFT);
 	fixed_t rollMul = FINECOSINE(viewingAngle >> ANGLETOFINESHIFT);
 
-	angle_t rollOrPitch = FixedMul(mobj->pitch, pitchMul) + FixedMul(mobj->roll, rollMul);
+	angle_t sloperolll = mobj->slopepitch;
+	angle_t slopepitch = mobj->sloperoll;
+
+	if (!cv_sloperoll.value)
+	{
+		sloperolll = 0;
+		slopepitch = 0;
+	}
+
+	angle_t rollOrPitch = FixedMul(mobj->pitch + sloperolll, pitchMul) + FixedMul(mobj->roll + slopepitch, rollMul);
 
 	return rollOrPitch;
 }