diff --git a/libs/vkd3d/resource.c b/libs/vkd3d/resource.c
index fcfc7e02..d7b8f542 100644
--- a/libs/vkd3d/resource.c
+++ b/libs/vkd3d/resource.c
@@ -621,9 +621,6 @@ static HRESULT d3d12_committed_resource_init(struct d3d12_resource *resource, st
 
     resource->desc = *desc;
 
-    if (optimized_clear_value)
-        FIXME("Ignoring optimized clear value.\n");
-
     if (desc->Dimension != D3D12_RESOURCE_DIMENSION_BUFFER
             && (heap_properties->Type == D3D12_HEAP_TYPE_UPLOAD || heap_properties->Type == D3D12_HEAP_TYPE_READBACK))
     {
@@ -642,6 +639,15 @@ static HRESULT d3d12_committed_resource_init(struct d3d12_resource *resource, st
         return E_INVALIDARG;
     }
 
+    if (optimized_clear_value && desc->Dimension == D3D12_RESOURCE_DIMENSION_BUFFER)
+    {
+        WARN("Optimized clear value must be NULL for buffers.\n");
+        return E_INVALIDARG;
+    }
+
+    if (optimized_clear_value)
+        FIXME("Ignoring optimized clear value.\n");
+
     switch (desc->Dimension)
     {
         case D3D12_RESOURCE_DIMENSION_BUFFER:
diff --git a/tests/d3d12.c b/tests/d3d12.c
index cf5388c8..818b56f2 100644
--- a/tests/d3d12.c
+++ b/tests/d3d12.c
@@ -890,20 +890,23 @@ static void test_create_committed_resource(void)
     refcount = ID3D12Resource_Release(resource);
     ok(!refcount, "ID3D12Resource has %u references left.\n", (unsigned int)refcount);
 
+    /* For D3D12_RESOURCE_STATE_RENDER_TARGET the D3D12_RESOURCE_FLAG_ALLOW_RENDER_TARGET flag is required. */
     resource_desc.Flags = 0;
     hr = ID3D12Device_CreateCommittedResource(device, &heap_properties, D3D12_HEAP_FLAG_NONE,
-            &resource_desc, D3D12_RESOURCE_STATE_RENDER_TARGET, &clear_value,
+            &resource_desc, D3D12_RESOURCE_STATE_RENDER_TARGET, NULL,
             &IID_ID3D12Resource, (void **)&resource);
     todo(hr == E_INVALIDARG, "Got unexpected hr %#x.\n", hr);
     if (SUCCEEDED(hr))
         ID3D12Resource_Release(resource);
 
+    /* A texture cannot be created on a UPLOAD heap. */
     heap_properties.Type = D3D12_HEAP_TYPE_UPLOAD;
     hr = ID3D12Device_CreateCommittedResource(device, &heap_properties, D3D12_HEAP_FLAG_NONE,
             &resource_desc, D3D12_RESOURCE_STATE_GENERIC_READ, NULL,
             &IID_ID3D12Resource, (void **)&resource);
     ok(hr == E_INVALIDARG, "Got unexpected hr %#x.\n", hr);
 
+    /* A texture cannot be created on a READBACK heap. */
     heap_properties.Type = D3D12_HEAP_TYPE_READBACK;
     hr = ID3D12Device_CreateCommittedResource(device, &heap_properties, D3D12_HEAP_FLAG_NONE,
             &resource_desc, D3D12_RESOURCE_STATE_COPY_DEST, NULL,
@@ -937,6 +940,12 @@ static void test_create_committed_resource(void)
     refcount = ID3D12Resource_Release(resource);
     ok(!refcount, "ID3D12Resource has %u references left.\n", (unsigned int)refcount);
 
+    /* The clear value must be NULL for buffers. */
+    hr = ID3D12Device_CreateCommittedResource(device, &heap_properties, D3D12_HEAP_FLAG_NONE,
+            &resource_desc, D3D12_RESOURCE_STATE_GENERIC_READ, &clear_value,
+            &IID_ID3D12Resource, (void **)&resource);
+    ok(hr == E_INVALIDARG, "Got unexpected hr %#x.\n", hr);
+
     /* For D3D12_HEAP_TYPE_UPLOAD the state must be D3D12_RESOURCE_STATE_GENERIC_READ. */
     hr = ID3D12Device_CreateCommittedResource(device, &heap_properties, D3D12_HEAP_FLAG_NONE,
             &resource_desc, D3D12_RESOURCE_STATE_COMMON, NULL,