diff --git a/src/Common.h b/src/Common.h
index 9fb62a5..c84f629 100644
--- a/src/Common.h
+++ b/src/Common.h
@@ -82,6 +82,8 @@
 
 static const float PI = 3.14159265358979323846264338327950288419716939937510582f;
 
+static const D3D12_RANGE EMPTY_RANGE = {0, 0};
+
 struct vec2
 {
     float x, y;
diff --git a/src/D3D12Sample.cpp b/src/D3D12Sample.cpp
index d7c71fc..a9c33fc 100644
--- a/src/D3D12Sample.cpp
+++ b/src/D3D12Sample.cpp
@@ -282,7 +282,7 @@
     }
 
     BYTE* pData;
-    HRESULT hr = pIntermediate->Map(0, NULL, reinterpret_cast<void**>(&pData));
+    HRESULT hr = pIntermediate->Map(0, &EMPTY_RANGE, reinterpret_cast<void**>(&pData));
     if (FAILED(hr))
     {
         return 0;
@@ -704,8 +704,7 @@
         cbvDesc.SizeInBytes = AlignUp<UINT>(sizeof(ConstantBuffer0_PS), 256);
         g_Device->CreateConstantBufferView(&cbvDesc, g_MainDescriptorHeap[i]->GetCPUDescriptorHandleForHeapStart());
 
-        D3D12_RANGE readRange{0, 0};
-        CHECK_HR( g_ConstantBufferUploadHeap[i]->Map(0, &readRange, &g_ConstantBufferAddress[i]) );
+        CHECK_HR( g_ConstantBufferUploadHeap[i]->Map(0, &EMPTY_RANGE, &g_ConstantBufferAddress[i]) );
     }
 
     // create input layout
@@ -1019,9 +1018,7 @@
             IID_PPV_ARGS(&g_CbPerObjectUploadHeaps[i])) );
         g_CbPerObjectUploadHeaps[i]->SetName(L"Constant Buffer Upload Resource Heap");
 
-        D3D12_RANGE readRange{0, 0};    // We do not intend to read from this resource on the CPU. (so end is less than or equal to begin)
-                                          // map the resource heap to get a gpu virtual address to the beginning of the heap
-        CHECK_HR( g_CbPerObjectUploadHeaps[i]->Map(0, &readRange, &g_CbPerObjectAddress[i]) );
+        CHECK_HR( g_CbPerObjectUploadHeaps[i]->Map(0, &EMPTY_RANGE, &g_CbPerObjectAddress[i]) );
     }
 
     // # TEXTURE
diff --git a/src/Tests.cpp b/src/Tests.cpp
index bc7b4a9..25b2517 100644
--- a/src/Tests.cpp
+++ b/src/Tests.cpp
@@ -677,7 +677,7 @@
         resources[i].allocation.reset(alloc);
 
         void* mappedPtr = NULL;
-        CHECK_HR( resources[i].resource->Map(0, NULL, &mappedPtr) );
+        CHECK_HR( resources[i].resource->Map(0, &EMPTY_RANGE, &mappedPtr) );
 
         FillData(mappedPtr, bufSize, i);
 
@@ -849,7 +849,7 @@
     for(UINT i = 0; i < count; ++i)
     {
         void* mappedPtr = nullptr;
-        CHECK_HR( resourcesUpload[i].resource->Map(0, NULL, &mappedPtr) );
+        CHECK_HR( resourcesUpload[i].resource->Map(0, &EMPTY_RANGE, &mappedPtr) );
 
         FillData(mappedPtr, bufSize, i);
 
@@ -894,8 +894,7 @@
         // Unmap every 3rd resource, leave others mapped.
         if((i % 3) != 0)
         {
-            const D3D12_RANGE writtenRange = {0, 0};
-            resourcesReadback[i].resource->Unmap(0, &writtenRange);
+            resourcesReadback[i].resource->Unmap(0, &EMPTY_RANGE);
         }
     }
 }
@@ -927,7 +926,7 @@
 
     {
         void* mappedPtr = nullptr;
-        CHECK_HR( bufUpload.resource->Map(0, NULL, &mappedPtr) );
+        CHECK_HR( bufUpload.resource->Map(0, &EMPTY_RANGE, &mappedPtr) );
         FillData(mappedPtr, bufSize, 5236245);
         bufUpload.resource->Unmap(0, NULL);
     }
@@ -959,10 +958,11 @@
 
         bool isZero = false;
         {
+            const D3D12_RANGE readRange{0, bufSize}; // I could pass pReadRange = NULL but it generates D3D Debug layer warning: EXECUTION WARNING #930: MAP_INVALID_NULLRANGE
             void* mappedPtr = nullptr;
-            CHECK_HR( bufReadback.resource->Map(0, NULL, &mappedPtr) );
+            CHECK_HR( bufReadback.resource->Map(0, &readRange, &mappedPtr) );
             isZero = ValidateDataZero(mappedPtr, bufSize);
-            bufReadback.resource->Unmap(0, NULL);
+            bufReadback.resource->Unmap(0, &EMPTY_RANGE);
         }
 
         wprintf(L"Should be zero: %u, is zero: %u\n", shouldBeZero ? 1 : 0, isZero ? 1 : 0);
@@ -1087,7 +1087,7 @@
                 res.allocation.reset(alloc);
                 
                 void* mappedPtr = nullptr;
-                CHECK_HR( res.resource->Map(0, NULL, &mappedPtr) );
+                CHECK_HR( res.resource->Map(0, &EMPTY_RANGE, &mappedPtr) );
 
                 FillData(mappedPtr, res.size, res.dataSeed);
 
@@ -1159,8 +1159,7 @@
                 // Unmap some of them, leave others mapped.
                 if((resIndex % 3) == 1)
                 {
-                    D3D12_RANGE writtenRange = {0, 0};
-                    resources[resIndex].resource->Unmap(0, &writtenRange);
+                    resources[resIndex].resource->Unmap(0, &EMPTY_RANGE);
                 } 
 
                 resources.pop_back();