diff --git a/lib/API/VK/Device.cpp b/lib/API/VK/Device.cpp
index f13dc8eac..45f766869 100644
--- a/lib/API/VK/Device.cpp
+++ b/lib/API/VK/Device.cpp
@@ -55,8 +55,12 @@ static VkFormat getVKFormat(DataFormat Format, int Channels) {
   case DataFormat::Float32:
     VKFormats(SFLOAT, 32) break;
   case DataFormat::Int64:
+    if (Channels == 2)
+      return VK_FORMAT_R32G32B32A32_SINT;
     VKFormats(SINT, 64) break;
   case DataFormat::UInt64:
+    if (Channels == 2)
+      return VK_FORMAT_R32G32B32A32_UINT;
     VKFormats(UINT, 64) break;
   case DataFormat::Float64:
     VKFormats(SFLOAT, 64) break;
diff --git a/test/Feature/TypedBuffer/64bit-vector.test b/test/Feature/TypedBuffer/64bit-vector.test
index 1d0a83d8d..449ac04e1 100644
--- a/test/Feature/TypedBuffer/64bit-vector.test
+++ b/test/Feature/TypedBuffer/64bit-vector.test
@@ -122,10 +122,8 @@ DescriptorSets:
 ...
 #--- end
 
-# This test is failing on Vulkan due to two separate issues.
-# Bug https://github.com/llvm/offload-test-suite/issues/1030
-# Bug https://github.com/llvm/offload-test-suite/issues/1037
-# XFAIL: Vulkan
+# Bug https://github.com/microsoft/DirectXShaderCompiler/issues/8615
+# XFAIL: DXC && Vulkan
 
 # REQUIRES: Int64
 # RUN: split-file %s %t