diff --git a/src/tests/end2end/DepthStencilCopyTests.cpp b/src/tests/end2end/DepthStencilCopyTests.cpp
index 8755097..c94738d 100644
--- a/src/tests/end2end/DepthStencilCopyTests.cpp
+++ b/src/tests/end2end/DepthStencilCopyTests.cpp
@@ -574,6 +574,9 @@
     // on some Intel drivers.
     DAWN_SUPPRESS_TEST_IF(IsMetal() && IsIntel());
 
+    // TODO(crbug.com/dawn/1273): Fails on Win11 with D3D12 debug layer and full validation
+    DAWN_SUPPRESS_TEST_IF(IsD3D12() && IsBackendValidationEnabled());
+
     // Create a stencil texture
     constexpr uint32_t kWidth = 4;
     constexpr uint32_t kHeight = 4;
diff --git a/src/tests/white_box/D3D12DescriptorHeapTests.cpp b/src/tests/white_box/D3D12DescriptorHeapTests.cpp
index 1401f48..c290b7f 100644
--- a/src/tests/white_box/D3D12DescriptorHeapTests.cpp
+++ b/src/tests/white_box/D3D12DescriptorHeapTests.cpp
@@ -740,6 +740,9 @@
     DAWN_TEST_UNSUPPORTED_IF(!mD3DDevice->IsToggleEnabled(
         dawn::native::Toggle::UseD3D12SmallShaderVisibleHeapForTesting));
 
+    // TODO(crbug.com/dawn/1255): Fails on Win11 with D3D12 debug layer and full validation
+    DAWN_SUPPRESS_TEST_IF(IsD3D12() && IsBackendValidationEnabled());
+
     // Create a solid filled texture.
     wgpu::TextureDescriptor descriptor;
     descriptor.dimension = wgpu::TextureDimension::e2D;