diff --git a/source/core/gameinput.cpp b/source/core/gameinput.cpp
index 679074254..6915679ec 100644
--- a/source/core/gameinput.cpp
+++ b/source/core/gameinput.cpp
@@ -448,16 +448,16 @@ enum
 	BLOODVIEWPITCH = (0x4000 >> SINSHIFTDELTA) - (DEFVIEWPITCH << (SINSHIFTDELTA - 1)), // 1408.
 };
 
-void PlayerHorizon::calcviewpitch(vec2_t const pos, binangle const ang, bool const aimmode, bool const canslopetilt, sectortype* const cursectnum, double const scaleAdjust, bool const climbing)
+void PlayerHorizon::calcviewpitch(vec2_t const pos, DAngle const ang, bool const aimmode, bool const canslopetilt, sectortype* const cursectnum, double const scaleAdjust, bool const climbing)
 {
 	if (cl_slopetilting && cursectnum != nullptr)
 	{
 		if (aimmode && canslopetilt) // If the floor is sloped
 		{
 			// Get a point, 512 (64 for Blood) units ahead of player's position
-			int const shift = -(isBlood() ? BLOODSINSHIFT : DEFSINSHIFT);
-			int const x = pos.X + ang.bcos(shift);
-			int const y = pos.Y + ang.bsin(shift);
+			int const shift = isBlood() ? BLOODSINSHIFT : DEFSINSHIFT;
+			int const x = pos.X + int(ang.Cos() * (1 << (BUILDSINBITS - shift)));
+			int const y = pos.Y + int(ang.Sin() * (1 << (BUILDSINBITS - shift)));
 			auto tempsect = cursectnum;
 			updatesector(x, y, &tempsect);
 
diff --git a/source/core/gameinput.h b/source/core/gameinput.h
index 9633fa60d..1ebb35247 100644
--- a/source/core/gameinput.h
+++ b/source/core/gameinput.h
@@ -24,13 +24,13 @@ struct PlayerHorizon
 
 	// Prototypes for functions in gameinput.cpp.
 	void applyinput(float const horz, ESyncBits* actions, double const scaleAdjust = 1);
-	void calcviewpitch(vec2_t const pos, binangle const ang, bool const aimmode, bool const canslopetilt, sectortype* const cursectnum, double const scaleAdjust = 1, bool const climbing = false);
-	void calcviewpitch(const DVector2& pos, binangle const ang, bool const aimmode, bool const canslopetilt, sectortype* const cursectnum, double const scaleAdjust = 1, bool const climbing = false)
+	void calcviewpitch(vec2_t const pos, DAngle const ang, bool const aimmode, bool const canslopetilt, sectortype* const cursectnum, double const scaleAdjust = 1, bool const climbing = false);
+	void calcviewpitch(const DVector2& pos, DAngle const ang, bool const aimmode, bool const canslopetilt, sectortype* const cursectnum, double const scaleAdjust = 1, bool const climbing = false)
 	{
 		vec2_t ps = { int(pos.X * worldtoint), int(pos.Y * worldtoint) };
 		calcviewpitch(ps, ang, aimmode, canslopetilt, cursectnum, scaleAdjust, climbing);
 	}
-	void calcviewpitch(const DVector3& pos, binangle const ang, bool const aimmode, bool const canslopetilt, sectortype* const cursectnum, double const scaleAdjust = 1, bool const climbing = false)
+	void calcviewpitch(const DVector3& pos, DAngle const ang, bool const aimmode, bool const canslopetilt, sectortype* const cursectnum, double const scaleAdjust = 1, bool const climbing = false)
 	{
 		vec2_t ps = { int(pos.X * worldtoint), int(pos.Y * worldtoint) };
 		calcviewpitch(ps, ang, aimmode, canslopetilt, cursectnum, scaleAdjust, climbing);
diff --git a/source/games/blood/src/player.cpp b/source/games/blood/src/player.cpp
index b5d6c0902..7cd7b55fc 100644
--- a/source/games/blood/src/player.cpp
+++ b/source/games/blood/src/player.cpp
@@ -1518,7 +1518,7 @@ void doslopetilting(PLAYER* pPlayer, double const scaleAdjust = 1)
 	auto plActor = pPlayer->actor;
 	int const florhit = pPlayer->actor->hit.florhit.type;
 	bool const va = plActor->xspr.height < 16 && (florhit == kHitSector || florhit == 0) ? 1 : 0;
-	pPlayer->horizon.calcviewpitch(plActor->int_pos().vec2, buildang(plActor->int_ang()), va, plActor->sector()->floorstat & CSTAT_SECTOR_SLOPE, plActor->sector(), scaleAdjust);
+	pPlayer->horizon.calcviewpitch(plActor->int_pos().vec2, DAngle::fromBuild(plActor->int_ang()), va, plActor->sector()->floorstat & CSTAT_SECTOR_SLOPE, plActor->sector(), scaleAdjust);
 }
 
 //---------------------------------------------------------------------------
diff --git a/source/games/duke/src/inlines.h b/source/games/duke/src/inlines.h
index 304510fa1..bc010d9e3 100644
--- a/source/games/duke/src/inlines.h
+++ b/source/games/duke/src/inlines.h
@@ -208,7 +208,7 @@ inline bool playrunning()
 inline void doslopetilting(player_struct* p, double const scaleAdjust = 1)
 {
 	bool const canslopetilt = p->on_ground && p->insector() && p->cursector->lotag != ST_2_UNDERWATER && (p->cursector->floorstat & CSTAT_SECTOR_SLOPE);
-	p->horizon.calcviewpitch(p->pos, p->angle.ang, p->aim_mode == 0, canslopetilt, p->cursector, scaleAdjust);
+	p->horizon.calcviewpitch(p->pos.XY(), DAngle::fromBam(p->angle.ang.asbam()), p->aim_mode == 0, canslopetilt, p->cursector, scaleAdjust);
 }
 
 //---------------------------------------------------------------------------
diff --git a/source/games/sw/src/player.cpp b/source/games/sw/src/player.cpp
index 8097dcfc6..2352ddd80 100644
--- a/source/games/sw/src/player.cpp
+++ b/source/games/sw/src/player.cpp
@@ -1592,7 +1592,7 @@ void SlipSlope(PLAYER* pp)
 void DoPlayerHorizon(PLAYER* pp, float const horz, double const scaleAdjust)
 {
     bool const canslopetilt = !(pp->Flags & (PF_FLYING|PF_SWIMMING|PF_DIVING|PF_CLIMBING|PF_JUMPING|PF_FALLING)) && pp->cursector && (pp->cursector->floorstat & CSTAT_SECTOR_SLOPE);
-    pp->horizon.calcviewpitch(pp->pos.vec2, pp->angle.ang, pp->input.actions & SB_AIMMODE, canslopetilt, pp->cursector, scaleAdjust, (pp->Flags & PF_CLIMBING));
+    pp->horizon.calcviewpitch(pp->pos.vec2, DAngle::fromBam(pp->angle.ang.asbam()), pp->input.actions & SB_AIMMODE, canslopetilt, pp->cursector, scaleAdjust, (pp->Flags & PF_CLIMBING));
     pp->horizon.applyinput(horz, &pp->input.actions, scaleAdjust);
 }