diff --git a/src/gl/renderer/gl_postprocess.cpp b/src/gl/renderer/gl_postprocess.cpp
index 9dc0dd99e..e13acda4a 100644
--- a/src/gl/renderer/gl_postprocess.cpp
+++ b/src/gl/renderer/gl_postprocess.cpp
@@ -198,7 +198,7 @@ void FGLRenderer::BloomScene()
 
 	// Add bloom back to scene texture:
 	mBuffers->BindSceneTextureFB();
-	glViewport(0, 0, mOutputViewport.width, mOutputViewport.height);
+	glViewport(mOutputViewport.left, mOutputViewport.top, mOutputViewport.width, mOutputViewport.height);
 	glEnable(GL_BLEND);
 	glBlendEquation(GL_FUNC_ADD);
 	glBlendFunc(GL_ONE, GL_ONE);
diff --git a/src/gl/renderer/gl_renderer.cpp b/src/gl/renderer/gl_renderer.cpp
index a1d8bb2a7..d2a0cb959 100644
--- a/src/gl/renderer/gl_renderer.cpp
+++ b/src/gl/renderer/gl_renderer.cpp
@@ -185,6 +185,7 @@ void FGLRenderer::SetOutputViewport(GL_IRECT *bounds)
 	{
 		mOutputViewport = *bounds;
 		mOutputViewportLB = *bounds;
+		mScreenViewport = *bounds;
 		return;
 	}
 
@@ -209,6 +210,12 @@ void FGLRenderer::SetOutputViewport(GL_IRECT *bounds)
 	int vw = viewwidth;
 	int vh = viewheight;
 
+	// The entire renderable area, including the 2D HUD
+	mScreenViewport.left = 0;
+	mScreenViewport.top = 0;
+	mScreenViewport.width = framebuffer->GetWidth();
+	mScreenViewport.height = framebuffer->GetHeight();
+
 	// Letterboxed viewport for the main scene
 	mOutputViewportLB.left = viewwindowx;
 	mOutputViewportLB.top = trueheight - bars - (height + viewwindowy - ((height - vh) / 2));
@@ -242,12 +249,8 @@ void FGLRenderer::Begin2D()
 			mBuffers->BindSceneFB();
 		else
 			mBuffers->BindHudFB();
-		glViewport(0, 0, mOutputViewport.width, mOutputViewport.height);
-	}
-	else
-	{
-		glViewport(mOutputViewport.left, mOutputViewport.top, mOutputViewport.width, mOutputViewport.height);
 	}
+	glViewport(mScreenViewport.left, mScreenViewport.top, mScreenViewport.width, mScreenViewport.height);
 
 	gl_RenderState.EnableFog(false);
 	gl_RenderState.Set2DMode(true);
diff --git a/src/gl/renderer/gl_renderer.h b/src/gl/renderer/gl_renderer.h
index ad2046cad..150d23f6a 100644
--- a/src/gl/renderer/gl_renderer.h
+++ b/src/gl/renderer/gl_renderer.h
@@ -106,6 +106,7 @@ public:
 	FSkyVertexBuffer *mSkyVBO;
 	FLightBuffer *mLights;
 
+	GL_IRECT mScreenViewport;
 	GL_IRECT mOutputViewportLB;
 	GL_IRECT mOutputViewport;
 	bool mDrawingScene2D = false;
diff --git a/src/gl/scene/gl_scene.cpp b/src/gl/scene/gl_scene.cpp
index b28e2c293..d0a9e23b9 100644
--- a/src/gl/scene/gl_scene.cpp
+++ b/src/gl/scene/gl_scene.cpp
@@ -157,10 +157,7 @@ void FGLRenderer::SetViewArea()
 
 void FGLRenderer::Reset3DViewport()
 {
-	if (FGLRenderBuffers::IsEnabled())
-		glViewport(0, 0, mOutputViewport.width, mOutputViewport.height);
-	else
-		glViewport(mOutputViewport.left, mOutputViewport.top, mOutputViewport.width, mOutputViewport.height);
+	glViewport(mOutputViewport.left, mOutputViewport.top, mOutputViewport.width, mOutputViewport.height);
 }
 
 //-----------------------------------------------------------------------------
@@ -171,20 +168,16 @@ void FGLRenderer::Reset3DViewport()
 
 void FGLRenderer::Set3DViewport(bool toscreen)
 {
-	const auto &bounds = mOutputViewportLB;
 	if (toscreen && FGLRenderBuffers::IsEnabled())
 	{
 		mBuffers->Setup(mOutputViewport.width, mOutputViewport.height);
 		mBuffers->BindSceneFB();
-		glViewport(0, 0, bounds.width, bounds.height);
-		glScissor(0, 0, bounds.width, bounds.height);
-	}
-	else
-	{
-		glViewport(bounds.left, bounds.top, bounds.width, bounds.height);
-		glScissor(bounds.left, bounds.top, bounds.width, bounds.height);
 	}
 
+	const auto &bounds = mOutputViewportLB;
+	glViewport(bounds.left, bounds.top, bounds.width, bounds.height);
+	glScissor(bounds.left, bounds.top, bounds.width, bounds.height);
+
 	glEnable(GL_SCISSOR_TEST);
 	
 	#ifdef _DEBUG
diff --git a/src/gl/system/gl_wipe.cpp b/src/gl/system/gl_wipe.cpp
index 4c6922e4f..781194ca4 100644
--- a/src/gl/system/gl_wipe.cpp
+++ b/src/gl/system/gl_wipe.cpp
@@ -233,7 +233,8 @@ bool OpenGLFrameBuffer::WipeDo(int ticks)
 	if (FGLRenderBuffers::IsEnabled())
 	{
 		GLRenderer->mBuffers->BindHudFB();
-		glViewport(0, 0, GLRenderer->mOutputViewport.width, GLRenderer->mOutputViewport.height);
+		const auto &bounds = GLRenderer->mScreenViewport;
+		glViewport(bounds.left, bounds.top, bounds.width, bounds.height);
 	}
 
 	bool done = ScreenWipe->Run(ticks, this);