diff --git a/src/gl/renderer/gl_renderer.h b/src/gl/renderer/gl_renderer.h
index 53c39f605..b661b6266 100644
--- a/src/gl/renderer/gl_renderer.h
+++ b/src/gl/renderer/gl_renderer.h
@@ -155,8 +155,6 @@ public:
 	FTextureID glPart;
 	FTextureID mirrorTexture;
 	
-	float mSky1Pos, mSky2Pos;
-
 	FRotator mAngles;
 	FVector2 mViewVector;
 
diff --git a/src/gl/scene/gl_portal.cpp b/src/gl/scene/gl_portal.cpp
index 47a619b77..1ddb6523c 100644
--- a/src/gl/scene/gl_portal.cpp
+++ b/src/gl/scene/gl_portal.cpp
@@ -70,7 +70,6 @@ int GLPortal::renderdepth;
 int GLPortal::PlaneMirrorMode;
 GLuint GLPortal::QueryObject;
 
-int		 GLPortal::instack[2];
 bool	 GLPortal::inskybox;
 
 UniqueList<GLSkyInfo> UniqueSkies;
@@ -442,7 +441,7 @@ void GLPortal::StartFrame()
 	if (renderdepth==0)
 	{
 		inskybox=false;
-		instack[sector_t::floor]=instack[sector_t::ceiling]=0;
+		screen->instack[sector_t::floor] = screen->instack[sector_t::ceiling] = 0;
 	}
 	renderdepth++;
 }
@@ -743,7 +742,7 @@ void GLSectorStackPortal::DrawContents()
 	GLRenderer->mViewActor = NULL;
 
 	// avoid recursions!
-	if (origin->plane != -1) instack[origin->plane]++;
+	if (origin->plane != -1) screen->instack[origin->plane]++;
 
 	drawer->SetupView(r_viewpoint.Pos.X, r_viewpoint.Pos.Y, r_viewpoint.Pos.Z, r_viewpoint.Angles.Yaw, !!(MirrorFlag&1), !!(PlaneMirrorFlag&1));
 	SaveMapSection();
@@ -762,7 +761,7 @@ void GLSectorStackPortal::DrawContents()
 	drawer->DrawScene(DM_PORTAL);
 	RestoreMapSection();
 
-	if (origin->plane != -1) instack[origin->plane]--;
+	if (origin->plane != -1) screen->instack[origin->plane]--;
 }
 
 //-----------------------------------------------------------------------------
@@ -789,7 +788,7 @@ void GLPlaneMirrorPortal::DrawContents()
 		return;
 	}
 	// A plane mirror needs to flip the portal exclusion logic because inside the mirror, up is down and down is up.
-	std::swap(instack[sector_t::floor], instack[sector_t::ceiling]);
+	std::swap(screen->instack[sector_t::floor], screen->instack[sector_t::ceiling]);
 
 	int old_pm = PlaneMirrorMode;
 
@@ -810,7 +809,7 @@ void GLPlaneMirrorPortal::DrawContents()
 	gl_RenderState.SetClipHeight(0.f, 0.f);
 	PlaneMirrorFlag--;
 	PlaneMirrorMode = old_pm;
-	std::swap(instack[sector_t::floor], instack[sector_t::ceiling]);
+	std::swap(screen->instack[sector_t::floor], screen->instack[sector_t::ceiling]);
 }
 
 void GLPlaneMirrorPortal::PushState()
diff --git a/src/gl/scene/gl_portal.h b/src/gl/scene/gl_portal.h
index 7401316ad..fbb817a20 100644
--- a/src/gl/scene/gl_portal.h
+++ b/src/gl/scene/gl_portal.h
@@ -64,7 +64,6 @@ public:
 	static GLSceneDrawer *drawer;
 	static int PlaneMirrorMode;
 	static int inupperstack;
-	static int	instack[2];
 	static bool	inskybox;
 
 private:
diff --git a/src/gl/scene/gl_scene.cpp b/src/gl/scene/gl_scene.cpp
index 11d53cd5d..8df73e032 100644
--- a/src/gl/scene/gl_scene.cpp
+++ b/src/gl/scene/gl_scene.cpp
@@ -672,12 +672,6 @@ sector_t * GLSceneDrawer::RenderViewpoint (AActor * camera, GL_IRECT * bounds, f
 	GLRenderer->mAngles.Pitch = (float)RAD2DEG(asin(angy / alen));
 	GLRenderer->mAngles.Roll.Degrees = r_viewpoint.Angles.Roll.Degrees;
 
-	// Scroll the sky
-	GLRenderer->mSky1Pos = (double)fmod((double)screen->FrameTime * (double)level.skyspeed1, 1024.f) * 90./256.;
-	GLRenderer->mSky2Pos = (double)fmod((double)screen->FrameTime * (double)level.skyspeed2, 1024.f) * 90./256.;
-
-
-
 	if (camera->player && camera->player-players==consoleplayer &&
 		((camera->player->cheats & CF_CHASECAM) || (r_deathcamera && camera->health <= 0)) && camera==camera->player->mo)
 	{
diff --git a/src/gl/scene/gl_sky.cpp b/src/gl/scene/gl_sky.cpp
index be9e5a13d..24bd48e93 100644
--- a/src/gl/scene/gl_sky.cpp
+++ b/src/gl/scene/gl_sky.cpp
@@ -33,9 +33,6 @@
 #include "hwrenderer/utility/hw_lighting.h"
 #include "hwrenderer/textures/hw_material.h"
 
-#include "gl/renderer/gl_renderer.h"
-#include "gl/scene/gl_portal.h"
-
 CVAR(Bool,gl_noskyboxes, false, 0)
 
 //==========================================================================
@@ -76,7 +73,7 @@ void GLSkyInfo::init(int sky1, PalEntry FadeColor)
 		if (level.flags&LEVEL_DOUBLESKY)
 		{
 			texture[1] = FMaterial::ValidateTexture(sky1texture, false, true);
-			x_offset[1] = GLRenderer->mSky1Pos;
+			x_offset[1] = hw_sky1pos;
 			doublesky = true;
 		}
 
@@ -86,13 +83,13 @@ void GLSkyInfo::init(int sky1, PalEntry FadeColor)
 			texture[0] = FMaterial::ValidateTexture(sky2texture, false, true);
 			skytexno1 = sky2texture;
 			sky2 = true;
-			x_offset[0] = GLRenderer->mSky2Pos;
+			x_offset[0] = hw_sky2pos;
 		}
 		else if (!doublesky)
 		{
 			texture[0] = FMaterial::ValidateTexture(sky1texture, false, true);
 			skytexno1 = sky1texture;
-			x_offset[0] = GLRenderer->mSky1Pos;
+			x_offset[0] = hw_sky1pos;
 		}
 	}
 	if (level.skyfog > 0)
@@ -124,7 +121,8 @@ void GLWall::SkyPlane(HWDrawInfo *di, sector_t *sector, int plane, bool allowref
 		GLSkyInfo skyinfo;
 		skyinfo.init(sector->sky, Colormap.FadeColor);
 		ptype = PORTALTYPE_SKY;
-		sky = UniqueSkies.Get(&skyinfo);
+		sky = &skyinfo;
+		PutPortal(di, ptype);
 	}
 	else if (sportal != nullptr)
 	{
@@ -139,7 +137,7 @@ void GLWall::SkyPlane(HWDrawInfo *di, sector_t *sector, int plane, bool allowref
 			{
 				if (sector->PortalBlocksView(plane)) return;
 
-				if (GLPortal::instack[1 - plane]) return;
+				if (screen->instack[1 - plane]) return;
 				ptype = PORTALTYPE_SECTORSTACK;
 				portal = glport;
 			}
@@ -192,7 +190,7 @@ void GLWall::SkyLine(HWDrawInfo *di, sector_t *fs, line_t *line)
 	{
 		skyinfo.init(fs->sky, Colormap.FadeColor);
 		ptype = PORTALTYPE_SKY;
-		sky = UniqueSkies.Get(&skyinfo);
+		sky = &skyinfo;
 	}
 	ztop[0] = zceil[0];
 	ztop[1] = zceil[1];
diff --git a/src/gl/scene/gl_walls_draw.cpp b/src/gl/scene/gl_walls_draw.cpp
index 93cf8ceef..3d1b0dc95 100644
--- a/src/gl/scene/gl_walls_draw.cpp
+++ b/src/gl/scene/gl_walls_draw.cpp
@@ -463,6 +463,7 @@ void FDrawInfo::AddPortal(GLWall *wall, int ptype)
 		break;
 
 	case PORTALTYPE_SKY:
+		wall->sky = UniqueSkies.Get(wall->sky);
 		portal = GLPortal::FindPortal(wall->sky);
 		if (!portal) portal = new GLSkyPortal(wall->sky);
 		portal->AddLine(wall);
diff --git a/src/r_sky.cpp b/src/r_sky.cpp
index 31a9ec491..9bc3d0fc1 100644
--- a/src/r_sky.cpp
+++ b/src/r_sky.cpp
@@ -51,6 +51,7 @@ bool		skystretch;
 
 fixed_t		sky1cyl,		sky2cyl;
 double		sky1pos,		sky2pos;
+float		hw_sky1pos, hw_sky2pos;
 
 CUSTOM_CVAR(Int, testskyoffset, 0, 0)
 {
@@ -170,5 +171,10 @@ void R_UpdateSky (uint64_t mstime)
 	double ms = (double)mstime * FRACUNIT;
 	sky1pos = ms * level.skyspeed1;
 	sky2pos = ms * level.skyspeed2;
+
+	// The hardware renderer uses a different value range and clamps it to a single rotation
+	hw_sky1pos = (float)(fmod((double(mstime) * level.skyspeed1), 1024.) * (90. / 256.));
+	hw_sky2pos = (float)(fmod((double(mstime) * level.skyspeed2), 1024.) * (90. / 256.));
+
 }
 
diff --git a/src/r_sky.h b/src/r_sky.h
index e186ad3ae..a6e4cae9f 100644
--- a/src/r_sky.h
+++ b/src/r_sky.h
@@ -34,6 +34,7 @@ extern FTextureID	skyflatnum;
 extern fixed_t		sky1cyl,		sky2cyl;
 extern FTextureID	sky1texture,	sky2texture;
 extern double		sky1pos,		sky2pos;
+extern float		hw_sky1pos, hw_sky2pos;
 extern double	skytexturemid;
 extern float	skyiscale;
 extern double	skyscale;
diff --git a/src/v_video.h b/src/v_video.h
index b976e5415..92f1dc37d 100644
--- a/src/v_video.h
+++ b/src/v_video.h
@@ -327,6 +327,7 @@ protected:
 
 public:
 	int hwcaps = 0;
+	int instack[2] = { 0,0 };	// this is globally maintained state for portal recursion avoidance.
 
 public:
 	DFrameBuffer (int width, int height, bool bgra);