diff --git a/src/dobjgc.cpp b/src/dobjgc.cpp
index 5779b3903c..03a7153291 100644
--- a/src/dobjgc.cpp
+++ b/src/dobjgc.cpp
@@ -79,8 +79,6 @@
 #include "g_levellocals.h"
 #include "events.h"
 
-void MarkACSThinker();
-
 // MACROS ------------------------------------------------------------------
 
 /*
@@ -326,13 +324,11 @@ static void MarkRoot()
 
 	Gray = NULL;
 	Mark(Args);
-	Mark(screen);
 	Mark(StatusBar);
 	M_MarkMenus();
 	Mark(DIntermissionController::CurrentIntermission);
 	DThinker::MarkRoots();
 	FCanvasTextureInfo::Mark();
-	MarkACSThinker();
 	Mark(E_FirstEventHandler);
 	Mark(E_LastEventHandler);
 	for (auto &s : level.sectorPortals)
diff --git a/src/dobjtype.cpp b/src/dobjtype.cpp
index 62a810969a..3d27b3a0dd 100644
--- a/src/dobjtype.cpp
+++ b/src/dobjtype.cpp
@@ -242,7 +242,6 @@ void PClass::StaticShutdown ()
 {
 	if (WP_NOCHANGE != nullptr)
 	{
-		WP_NOCHANGE->ObjectFlags |= OF_YesReallyDelete;
 		delete WP_NOCHANGE;
 	}
 
diff --git a/src/gl/system/gl_framebuffer.cpp b/src/gl/system/gl_framebuffer.cpp
index cef60ed7ab..24e6ee6264 100644
--- a/src/gl/system/gl_framebuffer.cpp
+++ b/src/gl/system/gl_framebuffer.cpp
@@ -52,7 +52,6 @@
 #include "gl/renderer/gl_2ddrawer.h"
 #include "gl_debug.h"
 
-IMPLEMENT_CLASS(OpenGLFrameBuffer, false, false)
 EXTERN_CVAR (Float, vid_brightness)
 EXTERN_CVAR (Float, vid_contrast)
 EXTERN_CVAR (Bool, vid_vsync)
diff --git a/src/gl/system/gl_framebuffer.h b/src/gl/system/gl_framebuffer.h
index 72bdb73158..0d88667ca9 100644
--- a/src/gl/system/gl_framebuffer.h
+++ b/src/gl/system/gl_framebuffer.h
@@ -17,13 +17,11 @@ extern long gl_frameMS;
 class OpenGLFrameBuffer : public Win32GLFrameBuffer
 {
 	typedef Win32GLFrameBuffer Super;
-	DECLARE_CLASS(OpenGLFrameBuffer, Win32GLFrameBuffer)
 #else
 #include "sdlglvideo.h"
 class OpenGLFrameBuffer : public SDLGLFB
 {
-//	typedef SDLGLFB Super;	//[C]commented, DECLARE_CLASS defines this in linux
-	DECLARE_CLASS(OpenGLFrameBuffer, SDLGLFB)
+	typedef SDLGLFB Super;	//[C]commented, DECLARE_CLASS defines this in linux
 #endif
 
 
diff --git a/src/gl/system/gl_swframebuffer.cpp b/src/gl/system/gl_swframebuffer.cpp
index 4a97eb95be..7b9e54cfbd 100644
--- a/src/gl/system/gl_swframebuffer.cpp
+++ b/src/gl/system/gl_swframebuffer.cpp
@@ -113,8 +113,6 @@ DFrameBuffer *CreateGLSWFrameBuffer(int width, int height, bool bgra, bool fulls
 }
 #endif
 
-IMPLEMENT_CLASS(OpenGLSWFrameBuffer, false, false)
-
 const char *const OpenGLSWFrameBuffer::ShaderDefines[OpenGLSWFrameBuffer::NUM_SHADERS] =
 {
 	"#define ENORMALCOLOR", // NormalColor
diff --git a/src/gl/system/gl_swframebuffer.h b/src/gl/system/gl_swframebuffer.h
index 0f9c0a0efb..dcb67e138d 100644
--- a/src/gl/system/gl_swframebuffer.h
+++ b/src/gl/system/gl_swframebuffer.h
@@ -17,13 +17,11 @@ class FGLDebug;
 class OpenGLSWFrameBuffer : public Win32GLFrameBuffer
 {
 	typedef Win32GLFrameBuffer Super;
-	DECLARE_CLASS(OpenGLSWFrameBuffer, Win32GLFrameBuffer)
 #else
 #include "sdlglvideo.h"
 class OpenGLSWFrameBuffer : public SDLGLFB
 {
-//	typedef SDLGLFB Super;	//[C]commented, DECLARE_CLASS defines this in linux
-	DECLARE_CLASS(OpenGLSWFrameBuffer, SDLGLFB)
+	typedef SDLGLFB Super;	//[C]commented, DECLARE_CLASS defines this in linux
 #endif
 
 
diff --git a/src/p_acs.cpp b/src/p_acs.cpp
index b510ee45fe..dd75f90697 100644
--- a/src/p_acs.cpp
+++ b/src/p_acs.cpp
@@ -11022,11 +11022,6 @@ CCMD(acsprofile)
 	ShowProfileData(FuncProfiles, limit, sorter, true);
 }
 
-void MarkACSThinker()
-{
-	GC::Mark(DACSThinker::ActiveThinker);
-}
-
 ADD_STAT(ACS)
 {
 	return FStringf("ACS time: %f ms", ACSTime.TimeMS());
diff --git a/src/posix/cocoa/i_video.mm b/src/posix/cocoa/i_video.mm
index fd09c88f82..298aee3a30 100644
--- a/src/posix/cocoa/i_video.mm
+++ b/src/posix/cocoa/i_video.mm
@@ -632,7 +632,6 @@ DFrameBuffer* CocoaVideo::CreateFrameBuffer(const int width, const int height, c
 		}
 
 		old->GetFlash(flashColor, flashAmount);
-		old->ObjectFlags |= OF_YesReallyDelete;
 
 		if (old == screen)
 		{
@@ -1306,7 +1305,6 @@ void I_ShutdownGraphics()
 {
 	if (NULL != screen)
 	{
-		screen->ObjectFlags |= OF_YesReallyDelete;
 		delete screen;
 		screen = NULL;
 	}
diff --git a/src/posix/sdl/hardware.cpp b/src/posix/sdl/hardware.cpp
index 88870cb52d..7c9f66d832 100644
--- a/src/posix/sdl/hardware.cpp
+++ b/src/posix/sdl/hardware.cpp
@@ -95,7 +95,6 @@ void I_ShutdownGraphics ()
 	{
 		DFrameBuffer *s = screen;
 		screen = NULL;
-		s->ObjectFlags |= OF_YesReallyDelete;
 		delete s;
 	}
 	if (Video)
diff --git a/src/posix/sdl/sdlglvideo.cpp b/src/posix/sdl/sdlglvideo.cpp
index 1e602f102e..196f2034b0 100644
--- a/src/posix/sdl/sdlglvideo.cpp
+++ b/src/posix/sdl/sdlglvideo.cpp
@@ -30,9 +30,6 @@
 
 // TYPES -------------------------------------------------------------------
 
-IMPLEMENT_CLASS(SDLBaseFB, true, false)
-IMPLEMENT_CLASS(SDLGLFB, true, false)
-
 struct MiniModeInfo
 {
 	uint16_t Width, Height;
diff --git a/src/posix/sdl/sdlglvideo.h b/src/posix/sdl/sdlglvideo.h
index de37abbf4b..69472c8484 100644
--- a/src/posix/sdl/sdlglvideo.h
+++ b/src/posix/sdl/sdlglvideo.h
@@ -37,7 +37,7 @@ private:
 
 class SDLBaseFB : public DFrameBuffer
 {
-	DECLARE_CLASS(SDLBaseFB, DFrameBuffer)
+	typedef DFrameBuffer Super;
 public:
 	using DFrameBuffer::DFrameBuffer;
 	virtual SDL_Window *GetSDLWindow() = 0;
@@ -47,7 +47,7 @@ public:
 
 class SDLGLFB : public SDLBaseFB
 {
-	DECLARE_CLASS(SDLGLFB, SDLBaseFB)
+	typedef SDLBaseFB Super;
 public:
 	// this must have the same parameters as the Windows version, even if they are not used!
 	SDLGLFB (void *hMonitor, int width, int height, int, int, bool fullscreen, bool bgra); 
diff --git a/src/posix/sdl/sdlvideo.cpp b/src/posix/sdl/sdlvideo.cpp
index 030129fc00..4c830fe6cf 100644
--- a/src/posix/sdl/sdlvideo.cpp
+++ b/src/posix/sdl/sdlvideo.cpp
@@ -24,8 +24,6 @@
 
 // TYPES -------------------------------------------------------------------
 
-IMPLEMENT_CLASS(SDLFB, false, false)
-
 struct MiniModeInfo
 {
 	uint16_t Width, Height;
diff --git a/src/posix/sdl/sdlvideo.h b/src/posix/sdl/sdlvideo.h
index 001d6c0880..31a168aa64 100644
--- a/src/posix/sdl/sdlvideo.h
+++ b/src/posix/sdl/sdlvideo.h
@@ -4,7 +4,7 @@
 
 class SDLFB : public SDLBaseFB
 {
-	DECLARE_CLASS(SDLFB, SDLBaseFB)
+	typedef SDLBaseFB Super;
 public:
 	SDLFB(int width, int height, bool bgra, bool fullscreen, SDL_Window *oldwin);
 	~SDLFB();
diff --git a/src/swrenderer/r_swrenderer.cpp b/src/swrenderer/r_swrenderer.cpp
index 9f6da2a149..de1172740d 100644
--- a/src/swrenderer/r_swrenderer.cpp
+++ b/src/swrenderer/r_swrenderer.cpp
@@ -206,7 +206,6 @@ void FSoftwareRenderer::WriteSavePic (player_t *player, FileWriter *file, int wi
 	PalEntry palette[256];
 
 	// Take a snapshot of the player's view
-	pic->ObjectFlags |= OF_Fixed;
 	pic->Lock ();
 	if (r_polyrenderer)
 	{
@@ -227,8 +226,6 @@ void FSoftwareRenderer::WriteSavePic (player_t *player, FileWriter *file, int wi
 	screen->GetFlashedPalette (palette);
 	M_CreatePNG (file, pic->GetBuffer(), palette, SS_PAL, width, height, pic->GetPitch());
 	pic->Unlock ();
-	pic->Destroy();
-	pic->ObjectFlags |= OF_YesReallyDelete;
 	delete pic;
 }
 
diff --git a/src/textures/canvastexture.cpp b/src/textures/canvastexture.cpp
index ed72b0eee3..eba5d2feac 100644
--- a/src/textures/canvastexture.cpp
+++ b/src/textures/canvastexture.cpp
@@ -114,7 +114,6 @@ void FCanvasTexture::MakeTexture ()
 {
 	Canvas = new DSimpleCanvas (Width, Height, false);
 	Canvas->Lock ();
-	GC::AddSoftRoot(Canvas);
 
 	if (Width != Height || Width != Canvas->GetPitch())
 	{
@@ -136,7 +135,6 @@ void FCanvasTexture::MakeTextureBgra()
 {
 	CanvasBgra = new DSimpleCanvas(Width, Height, true);
 	CanvasBgra->Lock();
-	GC::AddSoftRoot(CanvasBgra);
 
 	if (Width != Height || Width != CanvasBgra->GetPitch())
 	{
@@ -172,16 +170,12 @@ void FCanvasTexture::Unload ()
 
 	if (Canvas != NULL)
 	{
-		GC::DelSoftRoot(Canvas);
-		Canvas->Destroy();
-		Canvas = NULL;
+		delete Canvas;
 	}
 
 	if (CanvasBgra != NULL)
 	{
-		GC::DelSoftRoot(CanvasBgra);
-		CanvasBgra->Destroy();
-		CanvasBgra = NULL;
+		delete CanvasBgra;
 	}
 
 	FTexture::Unload();
diff --git a/src/v_video.cpp b/src/v_video.cpp
index 96b45fad66..49cf088ea8 100644
--- a/src/v_video.cpp
+++ b/src/v_video.cpp
@@ -73,8 +73,6 @@ int active_con_scale();
 
 FRenderer *Renderer;
 
-IMPLEMENT_CLASS(DCanvas, true, false)
-IMPLEMENT_CLASS(DFrameBuffer, true, false)
 EXTERN_CVAR (Bool, swtruecolor)
 EXTERN_CVAR (Bool, fullscreen)
 
@@ -86,7 +84,7 @@ EXTERN_CVAR (Bool, fullscreen)
 
 class DDummyFrameBuffer : public DFrameBuffer
 {
-	DECLARE_CLASS (DDummyFrameBuffer, DFrameBuffer);
+	typedef DFrameBuffer Super;
 public:
 	DDummyFrameBuffer (int width, int height)
 		: DFrameBuffer (0, 0, false)
@@ -112,11 +110,6 @@ public:
 
 	float Gamma;
 };
-IMPLEMENT_CLASS(DDummyFrameBuffer, true, false)
-
-// SimpleCanvas is not really abstract, but this macro does not
-// try to generate a CreateNew() function.
-IMPLEMENT_CLASS(DSimpleCanvas, true, false)
 
 class FPaletteTester : public FTexture
 {
@@ -1272,7 +1265,6 @@ bool V_DoModeSetup (int width, int height, int bits)
 	}
 
 	screen = buff;
-	GC::WriteBarrier(screen);
 	screen->SetGamma (Gamma);
 
 	// Load fonts now so they can be packed into textures straight away,
@@ -1544,7 +1536,6 @@ void V_Init (bool restart)
 
 void V_Init2()
 {
-	assert (screen->IsKindOf(RUNTIME_CLASS(DDummyFrameBuffer)));
 	int width = screen->GetWidth();
 	int height = screen->GetHeight();
 	float gamma = static_cast<DDummyFrameBuffer *>(screen)->Gamma;
@@ -1552,7 +1543,6 @@ void V_Init2()
 	{
 		DFrameBuffer *s = screen;
 		screen = NULL;
-		s->ObjectFlags |= OF_YesReallyDelete;
 		delete s;
 	}
 
@@ -1579,7 +1569,6 @@ void V_Shutdown()
 	{
 		DFrameBuffer *s = screen;
 		screen = NULL;
-		s->ObjectFlags |= OF_YesReallyDelete;
 		delete s;
 	}
 	V_ClearFonts();
diff --git a/src/v_video.h b/src/v_video.h
index 56cb3ee0db..c4f9bdb954 100644
--- a/src/v_video.h
+++ b/src/v_video.h
@@ -198,9 +198,8 @@ struct VMVa_List
 //
 // [RH] Made screens more implementation-independant:
 //
-class DCanvas : public DObject
+class DCanvas
 {
-	DECLARE_ABSTRACT_CLASS (DCanvas, DObject)
 public:
 	DCanvas (int width, int height, bool bgra);
 	virtual ~DCanvas ();
@@ -317,7 +316,7 @@ private:
 
 class DSimpleCanvas : public DCanvas
 {
-	DECLARE_CLASS (DSimpleCanvas, DCanvas)
+	typedef DCanvas Super;
 public:
 	DSimpleCanvas (int width, int height, bool bgra);
 	~DSimpleCanvas ();
@@ -357,7 +356,7 @@ public:
 
 class DFrameBuffer : public DSimpleCanvas
 {
-	DECLARE_ABSTRACT_CLASS (DFrameBuffer, DSimpleCanvas)
+	typedef DSimpleCanvas Super;
 public:
 	DFrameBuffer (int width, int height, bool bgra);
 
diff --git a/src/win32/fb_d3d9.cpp b/src/win32/fb_d3d9.cpp
index 85331a3473..188d2530e4 100644
--- a/src/win32/fb_d3d9.cpp
+++ b/src/win32/fb_d3d9.cpp
@@ -92,8 +92,6 @@
 
 // TYPES -------------------------------------------------------------------
 
-IMPLEMENT_CLASS(D3DFB, false, false)
-
 struct D3DFB::PackedTexture
 {
 	D3DFB::Atlas *Owner;
diff --git a/src/win32/fb_ddraw.cpp b/src/win32/fb_ddraw.cpp
index b7f314608f..729bbaa916 100644
--- a/src/win32/fb_ddraw.cpp
+++ b/src/win32/fb_ddraw.cpp
@@ -60,8 +60,6 @@
 
 // TYPES -------------------------------------------------------------------
 
-IMPLEMENT_CLASS(DDrawFB, false, false)
-
 // EXTERNAL FUNCTION PROTOTYPES --------------------------------------------
 
 // PUBLIC FUNCTION PROTOTYPES ----------------------------------------------
diff --git a/src/win32/hardware.cpp b/src/win32/hardware.cpp
index 70e622b391..fa5e82e528 100644
--- a/src/win32/hardware.cpp
+++ b/src/win32/hardware.cpp
@@ -142,7 +142,6 @@ void I_ShutdownGraphics ()
 	{
 		DFrameBuffer *s = screen;
 		screen = NULL;
-		s->ObjectFlags |= OF_YesReallyDelete;
 		delete s;
 	}
 	if (Video)
diff --git a/src/win32/win32gliface.cpp b/src/win32/win32gliface.cpp
index 2074a17d8b..96c1510df4 100644
--- a/src/win32/win32gliface.cpp
+++ b/src/win32/win32gliface.cpp
@@ -945,8 +945,6 @@ bool Win32GLVideo::SetFullscreen(const char *devicename, int w, int h, int bits,
 //
 //==========================================================================
 
-IMPLEMENT_CLASS(Win32GLFrameBuffer, true, false)
-
 //==========================================================================
 //
 // 
diff --git a/src/win32/win32gliface.h b/src/win32/win32gliface.h
index ca949c864f..09e9e56420 100644
--- a/src/win32/win32gliface.h
+++ b/src/win32/win32gliface.h
@@ -27,7 +27,7 @@ FRenderer *gl_CreateInterface();
 
 class Win32GLFrameBuffer : public BaseWinFB
 {
-	DECLARE_CLASS(Win32GLFrameBuffer, BaseWinFB)
+	typedef BaseWinFB Super;
 
 public:
 	Win32GLFrameBuffer() {}
diff --git a/src/win32/win32iface.h b/src/win32/win32iface.h
index 8e7768b64f..7ea1901352 100644
--- a/src/win32/win32iface.h
+++ b/src/win32/win32iface.h
@@ -103,7 +103,7 @@ class Win32Video : public IVideo
 
 class BaseWinFB : public DFrameBuffer
 {
-	DECLARE_ABSTRACT_CLASS(BaseWinFB, DFrameBuffer)
+	typedef DFrameBuffer Super;
 public:
 	BaseWinFB(int width, int height, bool bgra) : DFrameBuffer(width, height, bgra), Windowed(true) {}
 
diff --git a/src/win32/win32swiface.h b/src/win32/win32swiface.h
index 5c0a456e46..59101c6023 100644
--- a/src/win32/win32swiface.h
+++ b/src/win32/win32swiface.h
@@ -18,7 +18,7 @@ extern HANDLE FPSLimitEvent;
 
 class DDrawFB : public BaseWinFB
 {
-	DECLARE_CLASS(DDrawFB, BaseWinFB)
+	typedef BaseWinFB Super;
 public:
 	DDrawFB (int width, int height, bool fullscreen);
 	~DDrawFB ();
@@ -100,7 +100,7 @@ private:
 
 class D3DFB : public BaseWinFB
 {
-	DECLARE_CLASS(D3DFB, BaseWinFB)
+	typedef BaseWinFB Super;
 public:
 	D3DFB (UINT adapter, int width, int height, bool bgra, bool fullscreen);
 	~D3DFB ();
diff --git a/src/win32/win32video.cpp b/src/win32/win32video.cpp
index f734ac7891..0ef2781059 100644
--- a/src/win32/win32video.cpp
+++ b/src/win32/win32video.cpp
@@ -80,8 +80,6 @@
 
 // TYPES -------------------------------------------------------------------
 
-IMPLEMENT_CLASS(BaseWinFB, true, false)
-
 typedef IDirect3D9 *(WINAPI *DIRECT3DCREATE9FUNC)(UINT SDKVersion);
 typedef HRESULT (WINAPI *DIRECTDRAWCREATEFUNC)(GUID FAR *lpGUID, LPDIRECTDRAW FAR *lplpDD, IUnknown FAR *pUnkOuter);
 
@@ -662,8 +660,7 @@ DFrameBuffer *Win32Video::CreateFrameBuffer (int width, int height, bool bgra, b
 			return old;
 		}
 		old->GetFlash (flashColor, flashAmount);
-		old->ObjectFlags |= OF_YesReallyDelete;
-		if (old == screen) screen = NULL;
+		if (old == screen) screen = nullptr;
 		delete old;
 	}
 	else
@@ -700,7 +697,6 @@ DFrameBuffer *Win32Video::CreateFrameBuffer (int width, int height, bool bgra, b
 			{
 				hr = fb->GetHR ();
 			}
-			fb->ObjectFlags |= OF_YesReallyDelete;
 			delete fb;
 
 			LOG1 ("fb is bad: %08lx\n", hr);