diff --git a/src/gl/scene/gl_portal.cpp b/src/gl/scene/gl_portal.cpp
index 25b2ff236..9b86cbbe8 100644
--- a/src/gl/scene/gl_portal.cpp
+++ b/src/gl/scene/gl_portal.cpp
@@ -606,10 +606,7 @@ void GLSkyboxPortal::DrawContents(FDrawInfo *di)
 	di->SetViewArea();
 	ClearClipper(di);
 
-	int mapsection = R_PointInSubsector(r_viewpoint.Pos)->mapsection;
-
-	di->CurrentMapSections.Zero();
-	di->CurrentMapSections.Set(mapsection);
+	di->UpdateCurrentMapSection();
 
 	drawer->DrawScene(di, DM_SKYPORTAL);
 	portal->mFlags &= ~PORTSF_INSKYBOX;
@@ -770,6 +767,8 @@ void GLPlaneMirrorPortal::DrawContents(FDrawInfo *di)
 	drawer->SetupView(r_viewpoint.Pos.X, r_viewpoint.Pos.Y, r_viewpoint.Pos.Z, r_viewpoint.Angles.Yaw, !!(MirrorFlag & 1), !!(PlaneMirrorFlag & 1));
 	ClearClipper(di);
 
+	di->UpdateCurrentMapSection();
+
 	gl_RenderState.SetClipHeight(planez, PlaneMirrorMode < 0 ? -1.f : 1.f);
 	drawer->DrawScene(di, DM_PORTAL);
 	gl_RenderState.SetClipHeight(0.f, 0.f);
@@ -944,6 +943,8 @@ void GLMirrorPortal::DrawContents(FDrawInfo *di)
 	angle_t a1 = linedef->v2->GetClipAngle();
 	di->mClipper->SafeAddClipRange(a1,a2);
 
+	di->UpdateCurrentMapSection();
+
 	gl_RenderState.SetClipLine(linedef);
 	gl_RenderState.EnableClipLine(true);
 	drawer->DrawScene(di, DM_PORTAL);
diff --git a/src/gl/scene/gl_scenedrawer.h b/src/gl/scene/gl_scenedrawer.h
index d075e1418..3396c269c 100644
--- a/src/gl/scene/gl_scenedrawer.h
+++ b/src/gl/scene/gl_scenedrawer.h
@@ -32,7 +32,6 @@ public:
 
 	angle_t FrustumAngle();
 	void SetViewMatrix(float vx, float vy, float vz, bool mirror, bool planemirror);
-	void SetViewArea();
 	void SetupView(float vx, float vy, float vz, DAngle va, bool mirror, bool planemirror);
 	void SetViewAngle(DAngle viewangle);
 	void SetProjection(VSMatrix matrix);
diff --git a/src/hwrenderer/scene/hw_drawinfo.h b/src/hwrenderer/scene/hw_drawinfo.h
index e9db60a09..8bec0df27 100644
--- a/src/hwrenderer/scene/hw_drawinfo.h
+++ b/src/hwrenderer/scene/hw_drawinfo.h
@@ -175,6 +175,8 @@ public:
 	void PreparePlayerSprites(sector_t * viewsector, area_t in_area);
 	void PrepareTargeterSprites();
 
+	void UpdateCurrentMapSection();
+
 	virtual void DrawWall(GLWall *wall, int pass) = 0;
 	virtual void DrawFlat(GLFlat *flat, int pass, bool trans) = 0;
 	virtual void DrawSprite(GLSprite *sprite, int pass) = 0;
diff --git a/src/hwrenderer/scene/hw_renderhacks.cpp b/src/hwrenderer/scene/hw_renderhacks.cpp
index 57fef57e0..74c5b3f0e 100644
--- a/src/hwrenderer/scene/hw_renderhacks.cpp
+++ b/src/hwrenderer/scene/hw_renderhacks.cpp
@@ -86,6 +86,12 @@ void HWDrawInfo::ClearBuffers()
 	mClipPortal = nullptr;
 }
 
+void HWDrawInfo::UpdateCurrentMapSection()
+{
+	const int mapsection = R_PointInSubsector(r_viewpoint.Pos)->mapsection;
+	CurrentMapSections.Set(mapsection);
+}
+
 //==========================================================================
 //
 // Adds a subsector plane to a sector's render list