diff --git a/src/v_video.cpp b/src/v_video.cpp
index b9917a1cb..9d377b7fd 100644
--- a/src/v_video.cpp
+++ b/src/v_video.cpp
@@ -725,6 +725,21 @@ void DCanvas::CalcGamma (float gamma, BYTE gammalookup[256])
 DSimpleCanvas::DSimpleCanvas (int width, int height)
 	: DCanvas (width, height)
 {
+	MemBuffer = nullptr;
+	Resize(width, height);
+}
+
+void DSimpleCanvas::Resize(int width, int height)
+{
+	Width = width;
+	Height = height;
+
+	if (MemBuffer != NULL)
+	{
+		delete[] MemBuffer;
+		MemBuffer = NULL;
+	}
+
 	// Making the pitch a power of 2 is very bad for performance
 	// Try to maximize the number of cache lines that can be filled
 	// for each column drawing operation by making the pitch slightly
@@ -761,7 +776,7 @@ DSimpleCanvas::DSimpleCanvas (int width, int height)
 		}
 	}
 	MemBuffer = new BYTE[Pitch * height];
-	memset (MemBuffer, 0, Pitch * height);
+	memset(MemBuffer, 0, Pitch * height);
 }
 
 //==========================================================================
@@ -1259,7 +1274,6 @@ CCMD(clean)
 bool V_DoModeSetup (int width, int height, int bits)
 {
 	DFrameBuffer *buff = I_SetMode (width, height, screen);
-	int cx1, cx2;
 
 	if (buff == NULL)
 	{
@@ -1274,6 +1288,17 @@ bool V_DoModeSetup (int width, int height, int bits)
 	// if D3DFB is being used for the display.
 	FFont::StaticPreloadFonts();
 
+	DisplayBits = bits;
+	V_UpdateModeSize(width, height);
+
+	M_RefreshModesList ();
+
+	return true;
+}
+
+void V_UpdateModeSize (int width, int height)
+{
+	int cx1, cx2;
 	V_CalcCleanFacs(320, 200, width, height, &CleanXfac, &CleanYfac, &cx1, &cx2);
 
 	CleanWidth = width / CleanXfac;
@@ -1314,14 +1339,19 @@ bool V_DoModeSetup (int width, int height, int bits)
 
 	DisplayWidth = width;
 	DisplayHeight = height;
-	DisplayBits = bits;
 
 	R_OldBlend = ~0;
 	Renderer->OnModeSet();
-	
-	M_RefreshModesList ();
+}
 
-	return true;
+void V_OutputResized (int width, int height)
+{
+	V_UpdateModeSize(width, height);
+	setsizeneeded = true;
+	if (StatusBar != NULL)
+	{
+		StatusBar->ScreenSizeChanged();
+	}
 }
 
 void V_CalcCleanFacs (int designwidth, int designheight, int realwidth, int realheight, int *cleanx, int *cleany, int *_cx1, int *_cx2)
diff --git a/src/v_video.h b/src/v_video.h
index 4f0a78675..11a10c8d8 100644
--- a/src/v_video.h
+++ b/src/v_video.h
@@ -47,6 +47,8 @@ extern int CleanWidth_1, CleanHeight_1, CleanXfac_1, CleanYfac_1;
 extern int DisplayWidth, DisplayHeight, DisplayBits;
 
 bool V_DoModeSetup (int width, int height, int bits);
+void V_UpdateModeSize (int width, int height);
+void V_OutputResized (int width, int height);
 void V_CalcCleanFacs (int designwidth, int designheight, int realwidth, int realheight, int *cleanx, int *cleany, int *cx1=NULL, int *cx2=NULL);
 
 class FTexture;
@@ -300,6 +302,8 @@ public:
 	void Unlock ();
 
 protected:
+	void Resize(int width, int height);
+
 	BYTE *MemBuffer;
 
 	DSimpleCanvas() {}
diff --git a/src/win32/fb_d3d9.cpp b/src/win32/fb_d3d9.cpp
index efdced151..06bfa0569 100644
--- a/src/win32/fb_d3d9.cpp
+++ b/src/win32/fb_d3d9.cpp
@@ -1220,6 +1220,24 @@ void D3DFB::Flip()
 		CurrRenderTexture ^= RenderTextureToggle;
 		TempRenderTexture = RenderTexture[CurrRenderTexture];
 	}
+
+	if (Windowed)
+	{
+		RECT box;
+		GetClientRect(Window, &box);
+		if (box.right > 0 && box.right > 0 && (Width != box.right || Height != box.bottom))
+		{
+			Resize(box.right, box.bottom);
+
+			TrueHeight = Height;
+			PixelDoubling = 0;
+			LBOffsetI = 0;
+			LBOffset = 0.0f;
+			Reset();
+
+			V_OutputResized(Width, Height);
+		}
+	}
 }
 
 //==========================================================================
diff --git a/src/win32/i_input.cpp b/src/win32/i_input.cpp
index 2b0659c83..1e6390392 100644
--- a/src/win32/i_input.cpp
+++ b/src/win32/i_input.cpp
@@ -537,10 +537,18 @@ LRESULT CALLBACK WndProc (HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
 		if (screen && !VidResizing)
 		{
 			LPMINMAXINFO mmi = (LPMINMAXINFO)lParam;
-			RECT rect = { 0, 0, screen->GetWidth(), screen->GetHeight() };
-			AdjustWindowRectEx(&rect, WS_VISIBLE|WS_OVERLAPPEDWINDOW, FALSE, WS_EX_APPWINDOW);
-			mmi->ptMinTrackSize.x = rect.right - rect.left;
-			mmi->ptMinTrackSize.y = rect.bottom - rect.top;
+			if (screen->IsFullscreen())
+			{
+				RECT rect = { 0, 0, screen->GetWidth(), screen->GetHeight() };
+				AdjustWindowRectEx(&rect, WS_VISIBLE | WS_OVERLAPPEDWINDOW, FALSE, WS_EX_APPWINDOW);
+				mmi->ptMinTrackSize.x = rect.right - rect.left;
+				mmi->ptMinTrackSize.y = rect.bottom - rect.top;
+			}
+			else
+			{
+				mmi->ptMinTrackSize.x = 320;
+				mmi->ptMinTrackSize.y = 200;
+			}
 			return 0;
 		}
 		break;