diff --git a/gpu-dawn/src/dawn/dawn_native_mach.cpp b/gpu-dawn/src/dawn/dawn_native_mach.cpp
index 72d1a01b..38186acf 100644
--- a/gpu-dawn/src/dawn/dawn_native_mach.cpp
+++ b/gpu-dawn/src/dawn/dawn_native_mach.cpp
@@ -223,6 +223,9 @@ MACH_EXPORT const DawnProcTable* machDawnNativeGetProcs() {
 
 
 // typedef struct MachUtilsBackendBindingImpl* MachUtilsBackendBinding;
+//
+// This is a legacy method. If using OpenGL, it must be used to create a backend binding
+// as Dawn does not yet support the WGPUSurface API for OpenGL yet. https://bugs.chromium.org/p/dawn/issues/detail?id=269&q=surface&can=2
 MACH_EXPORT MachUtilsBackendBinding machUtilsCreateBinding(WGPUBackendType backendType, GLFWwindow* window, WGPUDevice device) {
     wgpu::BackendType cppBackendType;
     switch (backendType) {
@@ -259,10 +262,14 @@ MACH_EXPORT MachUtilsBackendBinding machUtilsCreateBinding(WGPUBackendType backe
     return reinterpret_cast<MachUtilsBackendBinding>(utils::CreateBinding(cppBackendType, window, device));
 }
 
+// This is a legacy method. If using OpenGL, it must be used to create a backend binding
+// as Dawn does not yet support the WGPUSurface API for OpenGL yet. https://bugs.chromium.org/p/dawn/issues/detail?id=269&q=surface&can=2
 MACH_EXPORT uint64_t machUtilsBackendBinding_getSwapChainImplementation(MachUtilsBackendBinding binding) {
     auto self = reinterpret_cast<utils::BackendBinding*>(binding);
     return self->GetSwapChainImplementation();
 }
+// This is a legacy method. If using OpenGL, it must be used to create a backend binding
+// as Dawn does not yet support the WGPUSurface API for OpenGL yet. https://bugs.chromium.org/p/dawn/issues/detail?id=269&q=surface&can=2
 MACH_EXPORT WGPUTextureFormat machUtilsBackendBinding_getPreferredSwapChainTextureFormat(MachUtilsBackendBinding binding) {
     auto self = reinterpret_cast<utils::BackendBinding*>(binding);
     return self->GetPreferredSwapChainTextureFormat();
diff --git a/gpu-dawn/src/dawn/dawn_native_mach.h b/gpu-dawn/src/dawn/dawn_native_mach.h
index 2b942461..a38ce345 100644
--- a/gpu-dawn/src/dawn/dawn_native_mach.h
+++ b/gpu-dawn/src/dawn/dawn_native_mach.h
@@ -103,8 +103,10 @@ typedef struct MachDawnNativeAdapterDiscoveryOptions_OpenGLES {
 } MachDawnNativeAdapterDiscoveryOptions_OpenGLES;
 
 // utils
+//
+// These are legacy methods. If using OpenGL, they must be used to create a backend binding
+// as Dawn does not yet support the WGPUSurface API for OpenGL yet. https://bugs.chromium.org/p/dawn/issues/detail?id=269&q=surface&can=2
 #include <GLFW/glfw3.h>
-
 typedef struct MachUtilsBackendBindingImpl* MachUtilsBackendBinding;
 MACH_EXPORT MachUtilsBackendBinding machUtilsCreateBinding(WGPUBackendType backendType, GLFWwindow* window, WGPUDevice device);
 MACH_EXPORT uint64_t machUtilsBackendBinding_getSwapChainImplementation(MachUtilsBackendBinding binding);