diff --git a/util/test/demos/d3d11/d3d11_groupshared.cpp b/util/test/demos/d3d11/d3d11_groupshared.cpp
index 36c997f69..36e84611f 100644
--- a/util/test/demos/d3d11/d3d11_groupshared.cpp
+++ b/util/test/demos/d3d11/d3d11_groupshared.cpp
@@ -61,7 +61,7 @@ void main(uint3 tid : SV_GroupThreadID)
   outval.z = tmp[tid.x ^ 1];
 
   // do calculation with our neighbour
-  tmp[tid.x] = tmp[tid.x] * tmp[tid.x ^ 1];
+  tmp[tid.x] = (1.0f + tmp[tid.x]) * (1.0f + tmp[tid.x ^ 1]);
 
   GroupMemoryBarrierWithGroupSync();
 
diff --git a/util/test/demos/d3d12/d3d12_groupshared.cpp b/util/test/demos/d3d12/d3d12_groupshared.cpp
index 8561190f1..c7b92a7b2 100644
--- a/util/test/demos/d3d12/d3d12_groupshared.cpp
+++ b/util/test/demos/d3d12/d3d12_groupshared.cpp
@@ -61,7 +61,7 @@ void main(uint3 tid : SV_GroupThreadID)
   outval.z = tmp[tid.x ^ 1];
 
   // do calculation with our neighbour
-  tmp[tid.x] = tmp[tid.x] * tmp[tid.x ^ 1];
+  tmp[tid.x] = (1.0f + tmp[tid.x]) * (1.0f + tmp[tid.x ^ 1]);
 
   GroupMemoryBarrierWithGroupSync();
 
diff --git a/util/test/demos/vk/vk_groupshared.cpp b/util/test/demos/vk/vk_groupshared.cpp
index a99d76419..b0ff38fc4 100644
--- a/util/test/demos/vk/vk_groupshared.cpp
+++ b/util/test/demos/vk/vk_groupshared.cpp
@@ -45,7 +45,7 @@ shared float tmp[64];
 
 layout(local_size_x = 64, local_size_y = 1, local_size_z = 1) in;
 
-define GroupMemoryBarrierWithGroupSync() memoryBarrierShared();groupMemoryBarrier();barrier();
+#define GroupMemoryBarrierWithGroupSync() memoryBarrierShared();groupMemoryBarrier();barrier();
 
 void main()
 {
@@ -74,7 +74,7 @@ void main()
   outval.z = tmp[tid.x ^ 1];
 
   // do calculation with our neighbour
-  tmp[tid.x] = tmp[tid.x] * tmp[tid.x ^ 1];
+  tmp[tid.x] = (1.0f + tmp[tid.x]) * (1.0f + tmp[tid.x ^ 1]);
 
   GroupMemoryBarrierWithGroupSync();