diff --git a/src/k_kart.c b/src/k_kart.c
index 129a8f555..eca635005 100644
--- a/src/k_kart.c
+++ b/src/k_kart.c
@@ -3420,7 +3420,7 @@ boolean K_TripwirePass(player_t *player)
 
 boolean K_MovingHorizontally(mobj_t *mobj)
 {
-	return (P_AproxDistance(mobj->momx, mobj->momy) / 5 > abs(mobj->momz));
+	return (P_AproxDistance(mobj->momx, mobj->momy) / 4 > abs(mobj->momz));
 }
 
 boolean K_WaterRun(mobj_t *mobj)
diff --git a/src/p_map.c b/src/p_map.c
index e235cb9a4..677954b43 100644
--- a/src/p_map.c
+++ b/src/p_map.c
@@ -2618,7 +2618,7 @@ increment_move
 		if (!(thing->flags & MF_NOCLIP))
 		{
 			//All things are affected by their scale.
-			fixed_t maxstep = P_GetThingStepUp(thing, x, y);
+			fixed_t maxstep = P_GetThingStepUp(thing, tryx, tryy);
 
 			if (tmceilingz - tmfloorz < thing->height)
 			{
diff --git a/src/p_mobj.c b/src/p_mobj.c
index 794e3a0be..d5924de51 100644
--- a/src/p_mobj.c
+++ b/src/p_mobj.c
@@ -3126,16 +3126,14 @@ boolean P_CanRunOnWater(mobj_t *mobj, ffloor_t *rover)
 	fixed_t surfaceheight = INT32_MAX;
 	fixed_t surfDiff = INT32_MAX;
 
-	fixed_t floorheight = INT32_MAX;
-	fixed_t floorDiff = INT32_MAX;
-
 	fixed_t mobjbottom = INT32_MAX;
 	fixed_t maxStep = INT32_MAX;
 	boolean doifit = false;
 
 	pslope_t *waterSlope = NULL;
-	angle_t ourZAng = 0;
-	angle_t waterZAng = 0;
+	angle_t moveDir = 0;
+	fixed_t ourZAng = 0;
+	fixed_t waterZAng = 0;
 
 	if (rover == NULL)
 	{
@@ -3169,20 +3167,36 @@ boolean P_CanRunOnWater(mobj_t *mobj, ffloor_t *rover)
 		return false;
 	}
 
-	if (mobj->standingslope != NULL)
+	moveDir = K_MomentumAngle(mobj);
+
+	if (mobj->standingslope != NULL && mobj->standingslope->zangle != 0)
 	{
-		ourZAng = mobj->standingslope->zangle;
+		angle_t dir = mobj->standingslope->xydirection;
+		angle_t workang = mobj->standingslope->zangle;
+		if (workang >= ANGLE_180)
+		{
+			workang = InvAngle(workang);
+			dir = InvAngle(dir);
+		}
+		ourZAng = P_ReturnThrustX(mobj, dir - moveDir, AngleFixed(workang));
 	}
 
 	waterSlope = (flip ? *rover->b_slope : *rover->t_slope);
-	if (waterSlope != NULL)
+	if (waterSlope != NULL && waterSlope->zangle != 0)
 	{
-		waterZAng = waterSlope->zangle;
+		angle_t dir = waterSlope->xydirection;
+		angle_t workang = waterSlope->zangle;
+		if (workang >= ANGLE_180)
+		{
+			workang = InvAngle(workang);
+			dir = InvAngle(dir);
+		}
+		waterZAng = P_ReturnThrustX(mobj, dir - moveDir, AngleFixed(workang));
 	}
 
-	if (ourZAng != waterZAng)
+	if (abs(ourZAng - waterZAng) > 11*FRACUNIT)
 	{
-		// The surface slopes are different.
+		// The surface slopes are too different.
 		return false;
 	}
 
@@ -3200,16 +3214,20 @@ boolean P_CanRunOnWater(mobj_t *mobj, ffloor_t *rover)
 	maxStep = P_GetThingStepUp(mobj, mobj->x, mobj->y);
 
 	surfDiff = flip ? (surfaceheight - mobjbottom) : (mobjbottom - surfaceheight);
+
+	// We start water run IF we can step onto it!
 	if (surfDiff <= maxStep && surfDiff >= 0)
 	{
-		// We start water run IF we can step-down!
-		floorheight = flip ? P_GetSectorCeilingZAt(mobj->subsector->sector, mobj->x, mobj->y) : P_GetSectorFloorZAt(mobj->subsector->sector, mobj->x, mobj->y);
-		floorDiff = flip ? (floorheight - mobjbottom) : (mobjbottom - floorheight);
-		if (floorDiff <= maxStep && floorDiff >= 0)
+		if (ourZAng < 0)
 		{
-			// ... but NOT if real floor is in range.
-			// FIXME: Count solid FOFs in this check
-			return false;
+			fixed_t floorheight = flip ? P_GetSectorCeilingZAt(mobj->subsector->sector, mobj->x, mobj->y) : P_GetSectorFloorZAt(mobj->subsector->sector, mobj->x, mobj->y);
+			fixed_t floorDiff = flip ? (floorheight - mobjbottom) : (mobjbottom - floorheight);
+			if (floorDiff <= maxStep && floorDiff >= -maxStep)
+			{
+				// ... but NOT if going down and real floor is in range.
+				// FIXME: Count solid FOFs in this check
+				return false;
+			}
 		}
 
 		return true;