diff --git a/src/p_map.cpp b/src/p_map.cpp
index 8e59d246e..8a5321cf3 100644
--- a/src/p_map.cpp
+++ b/src/p_map.cpp
@@ -3679,7 +3679,7 @@ struct aim_t
 		newtrace.bottompitch = newbottompitch;
 		newtrace.aimdir = position == sector_t::ceiling? aim_t::aim_up : aim_t::aim_down;
 		newtrace.startpos = { startpos.x + portal->scaleX, startpos.y + portal->scaleY, startpos.z };
-		newtrace.startfrac = frac + FixedDiv(FRACUNIT, attackrange);	// this is to skip the transition line to the portal which will produce a bogus opening
+		newtrace.startfrac = frac + FixedDiv(FRACUNIT, attackrange);	// this is to skip the transition line to the portal which would produce a bogus opening
 		newtrace.lastsector = P_PointInSector(newtrace.startpos.x + FixedMul(aimtrace.x, newtrace.startfrac) , newtrace.startpos.y + FixedMul(aimtrace.y, newtrace.startfrac));
 		newtrace.limitz = portal->threshold;
 		Printf("-----Entering %s portal from sector %d to sector %d\n", position ? "ceiling" : "floor", lastsector->sectornum, newtrace.lastsector->sectornum);
@@ -3690,6 +3690,45 @@ struct aim_t
 		Printf("-----Exiting %s portal\n", position ? "ceiling" : "floor");
 	}
 
+	//============================================================================
+	//
+	// traverses a line portal
+	// simply calling PortalRelocate does not work here because more needs to be set up
+	//
+	//============================================================================
+
+	void EnterLinePortal(line_t *li, fixed_t frac)
+	{
+		aim_t newtrace = Clone();
+
+		FLinePortal *port = li->getPortal();
+		line_t *dest = port->mDestination;
+
+		newtrace.toppitch = toppitch;
+		newtrace.bottompitch = bottompitch;
+		newtrace.aimdir = aimdir;
+		newtrace.unlinked = (port->mType != PORTT_LINKED);
+		newtrace.startpos = startpos;
+		newtrace.aimtrace = aimtrace;
+		P_TranslatePortalXY(li, dest, newtrace.startpos.x, newtrace.startpos.y);
+		P_TranslatePortalZ(li, dest, newtrace.startpos.z);
+		P_TranslatePortalVXVY(li, dest, newtrace.aimtrace.x, newtrace.aimtrace.y);
+
+		newtrace.startfrac = frac + FixedDiv(FRACUNIT, attackrange);	// this is to skip the transition line to the portal which would produce a bogus opening
+
+		fixed_t x = newtrace.startpos.x + FixedMul(newtrace.aimtrace.x, newtrace.startfrac);
+		fixed_t y = newtrace.startpos.y + FixedMul(newtrace.aimtrace.y, newtrace.startfrac);
+
+		newtrace.lastsector = P_PointInSector(x, y);
+		P_TranslatePortalZ(li, dest, limitz);
+		Printf("-----Entering line portal from sector %d to sector %d\n", lastsector->sectornum, newtrace.lastsector->sectornum);
+		newtrace.AimTraverse();
+		SetResult(linetarget, newtrace.linetarget);
+		SetResult(thing_friend, newtrace.thing_friend);
+		SetResult(thing_other, newtrace.thing_other);
+	}
+
+
 	//============================================================================
 	//
 	// PTR_AimTraverse
@@ -3759,6 +3798,13 @@ struct aim_t
 
 				Printf("Found line %d: toppitch = %f, bottompitch = %f\n", int(li - lines), ANGLE2DBL(toppitch), ANGLE2DBL(bottompitch));
 
+				if (li->isLinePortal() && frontflag == 0)
+				{
+					EnterLinePortal(li, in->frac);
+					return;
+				}
+
+
 				if (!(li->flags & ML_TWOSIDED) || (li->flags & ML_BLOCKEVERYTHING))
 					return;				// stop
 
@@ -3886,7 +3932,7 @@ struct aim_t
 			if (crossedffloors)
 			{
 				// if 3D floors were in the way do an extra visibility check for safety
-				if (!P_CheckSight(shootthing, th, SF_IGNOREVISIBILITY | SF_IGNOREWATERBOUNDARY))
+				if (!unlinked && !P_CheckSight(shootthing, th, SF_IGNOREVISIBILITY | SF_IGNOREWATERBOUNDARY))
 				{
 					// the thing can't be seen so we can safely exclude its range from our aiming field
 					if (thingtoppitch < toppitch)
diff --git a/src/p_maputl.cpp b/src/p_maputl.cpp
index a00bc3b87..11284a7bf 100644
--- a/src/p_maputl.cpp
+++ b/src/p_maputl.cpp
@@ -1616,7 +1616,7 @@ void FPathTraverse::init (fixed_t x1, fixed_t y1, fixed_t x2, fixed_t y2, int fl
 //
 //===========================================================================
 
-bool FPathTraverse::PortalRelocate(intercept_t *in, int flags, fixedvec3 *optpos)
+int FPathTraverse::PortalRelocate(intercept_t *in, int flags, fixedvec3 *optpos)
 {
 	if (!in->isaline || !in->d.line->isLinePortal()) return false;
 	if (P_PointOnLineSidePrecise(trace.x, trace.y, in->d.line) == 1) return false;
@@ -1636,7 +1636,7 @@ bool FPathTraverse::PortalRelocate(intercept_t *in, int flags, fixedvec3 *optpos
 	}
 	intercepts.Resize(intercept_index);
 	init(hitx, hity, endx, endy, flags, in->frac);
-	return true;
+	return in->d.line->getPortal()->mType == PORTT_LINKED? 1:-1;
 }
 
 //===========================================================================
diff --git a/src/p_maputl.h b/src/p_maputl.h
index 5b702a2d1..d8044303e 100644
--- a/src/p_maputl.h
+++ b/src/p_maputl.h
@@ -356,7 +356,7 @@ public:
 		init(x1, y1, x2, y2, flags, startfrac);
 	}
 	void init(fixed_t x1, fixed_t y1, fixed_t x2, fixed_t y2, int flags, fixed_t startfrac = 0);
-	bool PortalRelocate(intercept_t *in, int flags, fixedvec3 *optpos = NULL);
+	int PortalRelocate(intercept_t *in, int flags, fixedvec3 *optpos = NULL);
 	virtual ~FPathTraverse();
 	const divline_t &Trace() const { return trace; }
 };