diff --git a/renderdoc/data/glsl/texdisplay.frag b/renderdoc/data/glsl/texdisplay.frag
index 2bd9b629b..e02405f21 100644
--- a/renderdoc/data/glsl/texdisplay.frag
+++ b/renderdoc/data/glsl/texdisplay.frag
@@ -100,9 +100,11 @@ void main(void)
 	vec4 pre_range_col = col;
 
 	col = ((col - RangeMinimum)*InverseRangeSize);
-
-	col = mix(vec4(0,0,0,1), col, Channels);
-	pre_range_col = mix(vec4(0,0,0,1), pre_range_col, Channels);
+	
+	if(Channels.x < 0.5f) col.x = pre_range_col.x = 0.0f;
+	if(Channels.y < 0.5f) col.y = pre_range_col.y = 0.0f;
+	if(Channels.z < 0.5f) col.z = pre_range_col.z = 0.0f;
+	if(Channels.w < 0.5f) col.w = pre_range_col.w = 1.0f;
 	
 	// show nans, infs and negatives
 	if((OutputDisplayFormat & TEXDISPLAY_NANS) > 0)
diff --git a/renderdoc/data/hlsl/debugcbuffers.h b/renderdoc/data/hlsl/debugcbuffers.h
index b522a2b5a..9712bd1f3 100644
--- a/renderdoc/data/hlsl/debugcbuffers.h
+++ b/renderdoc/data/hlsl/debugcbuffers.h
@@ -87,7 +87,7 @@ cbuffer DebugPixelCBufferData REG(b0)
 	float Slice;
 	float ScalePS;
 	int SampleIdx;
-	int Padding;
+	float AlwaysZero;
 
 	int RawOutput;
 	float3 TextureResolutionPS;
diff --git a/renderdoc/data/hlsl/debugdisplay.hlsl b/renderdoc/data/hlsl/debugdisplay.hlsl
index 9e5b34c8a..d160cb172 100644
--- a/renderdoc/data/hlsl/debugdisplay.hlsl
+++ b/renderdoc/data/hlsl/debugdisplay.hlsl
@@ -120,8 +120,13 @@ float4 RENDERDOC_TexDisplayPS(v2f IN) : SV_Target0
 
 	col = ((col - RangeMinimum)*InverseRangeSize);
 
-	col = lerp(float4(0,0,0,1), col, Channels);
-	pre_range_col = lerp(float4(0,0,0,1), pre_range_col, Channels);
+	// workaround for D3DCompiler bug. For some reason it assumes texture samples can
+	// never come back as NaN, so involving a cbuffer value like this here ensures
+	// the below isnan()s don't get optimised out.
+	if(Channels.x < 0.5f) col.x = pre_range_col.x = AlwaysZero;
+	if(Channels.y < 0.5f) col.y = pre_range_col.y = AlwaysZero;
+	if(Channels.z < 0.5f) col.z = pre_range_col.z = AlwaysZero;
+	if(Channels.w < 0.5f) col.w = pre_range_col.w = 1.0f-AlwaysZero;
 
 	// show nans, infs and negatives
 	if(OutputDisplayFormat & TEXDISPLAY_NANS)
diff --git a/renderdoc/driver/d3d11/d3d11_debug.cpp b/renderdoc/driver/d3d11/d3d11_debug.cpp
index 937e7396f..259efc3ff 100644
--- a/renderdoc/driver/d3d11/d3d11_debug.cpp
+++ b/renderdoc/driver/d3d11/d3d11_debug.cpp
@@ -3301,6 +3301,8 @@ bool D3D11DebugManager::RenderTexture(TextureDisplay cfg, bool blendAlpha)
 	DebugVertexCBuffer vertexData;
 	DebugPixelCBufferData pixelData;
 
+	pixelData.AlwaysZero = 0.0f;
+
 	float x = cfg.offx;
 	float y = cfg.offy;
 	
@@ -3690,6 +3692,8 @@ void D3D11DebugManager::RenderCheckerboard(Vec3f light, Vec3f dark)
 
 	DebugPixelCBufferData pixelData;
 
+	pixelData.AlwaysZero = 0.0f;
+
 	pixelData.Channels = Vec4f(light.x, light.y, light.z, 0.0f);
 	pixelData.WireframeColour = dark;
 	
@@ -4597,6 +4601,8 @@ void D3D11DebugManager::RenderMesh(uint32_t frameID, uint32_t eventID, const vec
 
 	DebugPixelCBufferData pixelData;
 
+	pixelData.AlwaysZero = 0.0f;
+
 	pixelData.OutputDisplayFormat = MESHDISPLAY_SOLID;
 	pixelData.WireframeColour = Vec3f(0.0f, 0.0f, 0.0f);
 	FillCBuffer(m_DebugRender.GenericPSCBuffer, (float *)&pixelData, sizeof(DebugPixelCBufferData));