diff --git a/plugins/GSdx/Renderers/DX11/GSDevice11.cpp b/plugins/GSdx/Renderers/DX11/GSDevice11.cpp
index d58eaa042c..ab293e4dab 100644
--- a/plugins/GSdx/Renderers/DX11/GSDevice11.cpp
+++ b/plugins/GSdx/Renderers/DX11/GSDevice11.cpp
@@ -186,7 +186,7 @@ bool GSDevice11::Create(const std::shared_ptr<GSWnd> &wnd)
 
 	std::string convert_mstr[1];
 
-	convert_mstr[0] = format("%d", m_upscale_multiplier);
+	convert_mstr[0] = format("%d", m_upscale_multiplier ? m_upscale_multiplier : 1);
 
 	D3D_SHADER_MACRO convert_macro[] =
 	{
diff --git a/plugins/GSdx/Renderers/DX11/GSTextureFX11.cpp b/plugins/GSdx/Renderers/DX11/GSTextureFX11.cpp
index edab091551..bc8af7d2b7 100644
--- a/plugins/GSdx/Renderers/DX11/GSTextureFX11.cpp
+++ b/plugins/GSdx/Renderers/DX11/GSTextureFX11.cpp
@@ -233,7 +233,7 @@ void GSDevice11::SetupPS(PSSelector sel, const PSConstantBuffer* cb, PSSamplerSe
 		str[21] = format("%d", sel.dfmt);
 		str[22] = format("%d", sel.depth_fmt);
 		str[23] = format("%d", sel.fmt >> 2);
-		str[24] = format("%d", m_upscale_multiplier);
+		str[24] = format("%d", m_upscale_multiplier ? m_upscale_multiplier : 1);
 
 		D3D_SHADER_MACRO macro[] =
 		{
diff --git a/plugins/GSdx/Renderers/OpenGL/GSDeviceOGL.cpp b/plugins/GSdx/Renderers/OpenGL/GSDeviceOGL.cpp
index ef76508edc..8419fb1984 100644
--- a/plugins/GSdx/Renderers/OpenGL/GSDeviceOGL.cpp
+++ b/plugins/GSdx/Renderers/OpenGL/GSDeviceOGL.cpp
@@ -377,8 +377,10 @@ bool GSDeviceOGL::Create(const std::shared_ptr<GSWnd> &wnd)
 		GL_PUSH("GSDeviceOGL::Convert");
 
 		m_convert.cb = new GSUniformBufferOGL("Misc UBO", g_convert_index, sizeof(MiscConstantBuffer));
-		// Upload once and forget about it
-		m_misc_cb_cache.ScalingFactor = GSVector4i(theApp.GetConfigI("upscale_multiplier"));
+		// Upload once and forget about it.
+		// Use value of 1 when upscale multiplier is 0 for ScalingFactor,
+		// this is to avoid doing math with 0 in shader. It helps custom res be less broken.
+		m_misc_cb_cache.ScalingFactor = GSVector4i(theApp.GetConfigI("upscale_multiplier") ? theApp.GetConfigI("upscale_multiplier") : 1);
 		m_convert.cb->cache_upload(&m_misc_cb_cache);
 
 		theApp.LoadResource(IDR_CONVERT_GLSL, shader);