diff --git a/tests/d3d12.c b/tests/d3d12.c
index 04b40eda..4ddb341d 100644
--- a/tests/d3d12.c
+++ b/tests/d3d12.c
@@ -2568,7 +2568,7 @@ static void test_device_removed_reason(void)
     ok(!refcount, "ID3D12Device has %u references left.\n", (unsigned int)refcount);
 }
 
-static void test_map_texture(void)
+static void test_map_resource(void)
 {
     D3D12_HEAP_PROPERTIES heap_properties;
     D3D12_RESOURCE_DESC resource_desc;
@@ -2584,9 +2584,6 @@ static void test_map_texture(void)
         return;
     }
 
-    memset(&heap_properties, 0, sizeof(heap_properties));
-    heap_properties.Type = D3D12_HEAP_TYPE_DEFAULT;
-
     resource_desc.Dimension = D3D12_RESOURCE_DIMENSION_TEXTURE2D;
     resource_desc.Alignment = 0;
     resource_desc.Width = 32;
@@ -2599,6 +2596,8 @@ static void test_map_texture(void)
     resource_desc.Layout = D3D12_TEXTURE_LAYOUT_UNKNOWN;
     resource_desc.Flags = 0;
 
+    memset(&heap_properties, 0, sizeof(heap_properties));
+    heap_properties.Type = D3D12_HEAP_TYPE_DEFAULT;
     hr = ID3D12Device_CreateCommittedResource(device, &heap_properties, D3D12_HEAP_FLAG_NONE,
             &resource_desc, D3D12_RESOURCE_STATE_COMMON, NULL,
             &IID_ID3D12Resource, (void **)&resource);
@@ -2619,16 +2618,34 @@ static void test_map_texture(void)
     if (FAILED(hr))
     {
         skip("Failed to create texture on custom heap.\n");
-        goto failed;
+    }
+    else
+    {
+        /* The data pointer must be NULL for the UNKNOWN layout. */
+        hr = ID3D12Resource_Map(resource, 0, NULL, &data);
+        ok(hr == E_INVALIDARG, "Got unexpected hr %#x.\n", hr);
+
+        ID3D12Resource_Release(resource);
     }
 
-    /* The data pointer must be NULL for the UNKNOWN layout. */
+    resource_desc.Dimension = D3D12_RESOURCE_DIMENSION_BUFFER;
+    resource_desc.Height = 1;
+    resource_desc.Format = DXGI_FORMAT_UNKNOWN;
+    resource_desc.Layout = D3D12_TEXTURE_LAYOUT_ROW_MAJOR;
+
+    memset(&heap_properties, 0, sizeof(heap_properties));
+    heap_properties.Type = D3D12_HEAP_TYPE_DEFAULT;
+    hr = ID3D12Device_CreateCommittedResource(device, &heap_properties, D3D12_HEAP_FLAG_NONE,
+            &resource_desc, D3D12_RESOURCE_STATE_COMMON, NULL,
+            &IID_ID3D12Resource, (void **)&resource);
+    ok(SUCCEEDED(hr), "CreateCommittedResource failed, hr %#x.\n", hr);
+
+    /* Resources on a DEFAULT heap cannot be mapped. */
     hr = ID3D12Resource_Map(resource, 0, NULL, &data);
-    ok(hr == E_INVALIDARG, "Got unexpected hr %#x.\n", hr);
+    todo(hr == E_INVALIDARG, "Got unexpected hr %#x.\n", hr);
 
     ID3D12Resource_Release(resource);
 
-failed:
     refcount = ID3D12Device_Release(device);
     ok(!refcount, "ID3D12Device has %u references left.\n", (unsigned int)refcount);
 }
@@ -2662,5 +2679,5 @@ START_TEST(d3d12)
     test_draw_instanced();
     test_invalid_texture_resource_barriers();
     test_device_removed_reason();
-    test_map_texture();
+    test_map_resource();
 }