diff --git a/Source/Core/VideoBackends/D3D/Render.cpp b/Source/Core/VideoBackends/D3D/Render.cpp
index 230cb11ec4..63a0b708af 100644
--- a/Source/Core/VideoBackends/D3D/Render.cpp
+++ b/Source/Core/VideoBackends/D3D/Render.cpp
@@ -524,7 +524,7 @@ void Renderer::SetViewport()
 
 	D3D11_VIEWPORT vp = CD3D11_VIEWPORT(X, Y, Wd, Ht,
 		1.0f - MathUtil::Clamp<float>(xfmem.viewport.farZ, 0.0f, 16777215.0f) / 16777216.0f,
-		1.0f - MathUtil::Clamp<float>(xfmem.viewport.farZ - xfmem.viewport.zRange, 0.0f, 16777215.0f) / 16777216.0f);
+		1.0f - MathUtil::Clamp<float>((xfmem.viewport.farZ - MathUtil::Clamp<float>(xfmem.viewport.zRange, 0.0f, 16777215.0f)), 0.0f, 16777215.0f) / 16777216.0f);
 	D3D::context->RSSetViewports(1, &vp);
 }
 
diff --git a/Source/Core/VideoBackends/OGL/Render.cpp b/Source/Core/VideoBackends/OGL/Render.cpp
index 1b4038e57f..f04eef8ba2 100644
--- a/Source/Core/VideoBackends/OGL/Render.cpp
+++ b/Source/Core/VideoBackends/OGL/Render.cpp
@@ -1195,7 +1195,7 @@ void Renderer::SetViewport()
 	float Y = EFBToScaledYf((float)EFB_HEIGHT - xfmem.viewport.yOrig + xfmem.viewport.ht + (float)scissorYOff);
 	float Width = EFBToScaledXf(2.0f * xfmem.viewport.wd);
 	float Height = EFBToScaledYf(-2.0f * xfmem.viewport.ht);
-	float GLNear = MathUtil::Clamp<float>(xfmem.viewport.farZ - xfmem.viewport.zRange, 0.0f, 16777215.0f) / 16777216.0f;
+	float GLNear = MathUtil::Clamp<float>(xfmem.viewport.farZ - MathUtil::Clamp<float>(xfmem.viewport.zRange, 0.0f, 16777215.0f), 0.0f, 16777215.0f) / 16777216.0f;
 	float GLFar = MathUtil::Clamp<float>(xfmem.viewport.farZ, 0.0f, 16777215.0f) / 16777216.0f;
 	if (Width < 0)
 	{
diff --git a/Source/Core/VideoCommon/PixelShaderGen.cpp b/Source/Core/VideoCommon/PixelShaderGen.cpp
index d9d8c18599..ad251203f9 100644
--- a/Source/Core/VideoCommon/PixelShaderGen.cpp
+++ b/Source/Core/VideoCommon/PixelShaderGen.cpp
@@ -587,7 +587,7 @@ static inline void GeneratePixelShader(T& out, DSTALPHA_MODE dstAlphaMode, API_T
 		else
 			out.Write("\tint zCoord = int(rawpos.z * 16777216.0);\n");
 	}
-	out.Write("\tzCoord = clamp(zCoord, " I_ZBIAS"[1].x - " I_ZBIAS"[1].y, " I_ZBIAS"[1].x);\n");
+	out.Write("\tzCoord = clamp(zCoord, 0, 0xFFFFFF);\n");
 
 	// depth texture can safely be ignored if the result won't be written to the depth buffer (early_ztest) and isn't used for fog either
 	const bool skip_ztexture = !per_pixel_depth && !bpmem.fog.c_proj_fsel.fsel;
diff --git a/Source/Core/VideoCommon/PixelShaderManager.cpp b/Source/Core/VideoCommon/PixelShaderManager.cpp
index b67140d5b6..e388c15fcf 100644
--- a/Source/Core/VideoCommon/PixelShaderManager.cpp
+++ b/Source/Core/VideoCommon/PixelShaderManager.cpp
@@ -96,8 +96,8 @@ void PixelShaderManager::SetConstants()
 
 	if (s_bViewPortChanged)
 	{
-		constants.zbias[1][0] = MathUtil::Clamp<u32>((u32)xfmem.viewport.farZ, 0, 0xFFFFFF);
-		constants.zbias[1][1] = MathUtil::Clamp<u32>((u32)xfmem.viewport.zRange, 0, 0xFFFFFF);
+		constants.zbias[1][0] = (u32)xfmem.viewport.farZ;
+		constants.zbias[1][1] = (u32)xfmem.viewport.zRange;
 		dirty = true;
 		s_bViewPortChanged = false;
 	}