diff --git a/Source/Plugins/Plugin_VideoDX11/Src/Render.cpp b/Source/Plugins/Plugin_VideoDX11/Src/Render.cpp
index 19258256db..995e1f3a37 100644
--- a/Source/Plugins/Plugin_VideoDX11/Src/Render.cpp
+++ b/Source/Plugins/Plugin_VideoDX11/Src/Render.cpp
@@ -658,10 +658,10 @@ void Renderer::UpdateViewport()
 			ERROR_LOG(VIDEO, "Tried to set a viewport which is too wide to emulate with Direct3D11. Requested EFB size is %dx%d\n", Renderer::GetFullTargetWidth(), Renderer::GetFullTargetHeight());
 
 			// Fix the viewport to fit to the old EFB size, TODO: Check this for off-by-one errors
-			newx *= (float)old_fulltarget_w / (float)Renderer::GetFullTargetWidth();
-			newy *= (float)old_fulltarget_h / (float)Renderer::GetFullTargetHeight();
-			newwidth *= (float)old_fulltarget_w / (float)Renderer::GetFullTargetWidth();
-			newheight *= (float)old_fulltarget_h / (float)Renderer::GetFullTargetHeight();
+			newx *= (float)(old_fulltarget_w-1) / (float)(Renderer::GetFullTargetWidth()-1);
+			newy *= (float)(old_fulltarget_h-1) / (float)(Renderer::GetFullTargetHeight()-1);
+			newwidth *= (float)(old_fulltarget_w-1) / (float)(Renderer::GetFullTargetWidth()-1);
+			newheight *= (float)(old_fulltarget_h-1) / (float)(Renderer::GetFullTargetHeight()-1);
 
 			s_Fulltarget_width = old_fulltarget_w;
 			s_Fulltarget_height = old_fulltarget_h;
diff --git a/Source/Plugins/Plugin_VideoDX9/Src/Render.cpp b/Source/Plugins/Plugin_VideoDX9/Src/Render.cpp
index d6f63dbe23..a8a2e3df23 100644
--- a/Source/Plugins/Plugin_VideoDX9/Src/Render.cpp
+++ b/Source/Plugins/Plugin_VideoDX9/Src/Render.cpp
@@ -692,9 +692,6 @@ void Renderer::UpdateViewport()
 	int scissorXOff = bpmem.scissorOffset.x << 1;
 	int scissorYOff = bpmem.scissorOffset.y << 1;
 
-	int Xstride =  (Renderer::GetFullTargetWidth() - Renderer::GetTargetWidth()) / 2;
-	int Ystride =  (Renderer::GetFullTargetHeight() - Renderer::GetTargetHeight()) / 2;
-
 	// TODO: ceil, floor or just cast to int?
 	int X = EFBToScaledX((int)ceil(xfregs.rawViewport[3] - xfregs.rawViewport[0] - scissorXOff)) + TargetStrideX();
 	int Y = EFBToScaledY((int)ceil(xfregs.rawViewport[4] + xfregs.rawViewport[1] - scissorYOff)) + TargetStrideY();
@@ -740,16 +737,16 @@ void Renderer::UpdateViewport()
 	{
 		D3DCAPS9 caps = D3D::GetCaps();
 		// Make sure that the requested size is actually supported by the GFX driver
-		if (Renderer::GetFullTargetWidth() > caps.MaxTextureWidth || Renderer::GetFullTargetHeight() > caps.MaxTextureHeight)
+		if (Renderer::GetFullTargetWidth() > (int)caps.MaxTextureWidth || Renderer::GetFullTargetHeight() > (int)caps.MaxTextureHeight)
 		{
 			// Skip EFB recreation and viewport setting. Most likely causes glitches in this case, but prevents crashes at least
 			ERROR_LOG(VIDEO, "Tried to set a viewport which is too wide to emulate with Direct3D9. Requested EFB size is %dx%d, keeping the %dx%d EFB now\n", Renderer::GetFullTargetWidth(), Renderer::GetFullTargetHeight(), old_fulltarget_w, old_fulltarget_h);
 
-			// Fix the viewport to fit to the old EFB size, TODO: Check this for off-by-one errors
-			X *= old_fulltarget_w / Renderer::GetFullTargetWidth();
-			Y *= old_fulltarget_h / Renderer::GetFullTargetHeight();
-			Width *= old_fulltarget_w / Renderer::GetFullTargetWidth();
-			Height *= old_fulltarget_h / Renderer::GetFullTargetHeight();
+			// Fix the viewport to fit to the old EFB size
+			X *= (old_fulltarget_w-1) / (Renderer::GetFullTargetWidth()-1);
+			Y *= (old_fulltarget_h-1) / (Renderer::GetFullTargetHeight()-1);
+			Width *= (old_fulltarget_w-1) / (Renderer::GetFullTargetWidth()-1);
+			Height *= (old_fulltarget_h-1) / (Renderer::GetFullTargetHeight()-1);
 
 			s_Fulltarget_width = old_fulltarget_w;
 			s_Fulltarget_height = old_fulltarget_h;
diff --git a/Source/Plugins/Plugin_VideoOGL/Src/Render.cpp b/Source/Plugins/Plugin_VideoOGL/Src/Render.cpp
index d157ca9d1e..1cc71566c6 100644
--- a/Source/Plugins/Plugin_VideoOGL/Src/Render.cpp
+++ b/Source/Plugins/Plugin_VideoOGL/Src/Render.cpp
@@ -781,9 +781,6 @@ void Renderer::UpdateViewport()
 	int scissorXOff = bpmem.scissorOffset.x << 1;
 	int scissorYOff = bpmem.scissorOffset.y << 1;
 
-	// int Xstride =  (s_Fulltarget_width - s_target_width) / 2;
-	// int Ystride =  (s_Fulltarget_height - s_target_height) / 2;
-
 	// TODO: ceil, floor or just cast to int?
 	int X = EFBToScaledX((int)ceil(xfregs.rawViewport[3] - xfregs.rawViewport[0] - (float)scissorXOff));
 	int Y = EFBToScaledY((int)ceil((float)EFB_HEIGHT - xfregs.rawViewport[4] + xfregs.rawViewport[1] + (float)scissorYOff));