--- a/gfx/webrender_bindings/WebRenderTypes.h
+++ b/gfx/webrender_bindings/WebRenderTypes.h
@@ -71,32 +71,32 @@ SurfaceFormatToImageFormat(gfx::SurfaceF
       MOZ_ASSERT(false);
       return Nothing();
     case gfx::SurfaceFormat::B8G8R8X8:
       // TODO: WebRender will have a BGRA + opaque flag for this but does not
       // have it yet (cf. issue #732).
     case gfx::SurfaceFormat::B8G8R8A8:
       return Some(wr::ImageFormat::BGRA8);
     case gfx::SurfaceFormat::A8:
-      return Some(wr::ImageFormat::A8);
+      return Some(wr::ImageFormat::R8);
     case gfx::SurfaceFormat::R8G8:
       return Some(wr::ImageFormat::RG8);
     case gfx::SurfaceFormat::UNKNOWN:
       return Some(wr::ImageFormat::Invalid);
     default:
       return Nothing();
   }
 }
 
 inline gfx::SurfaceFormat
 ImageFormatToSurfaceFormat(ImageFormat aFormat) {
   switch (aFormat) {
     case ImageFormat::BGRA8:
       return gfx::SurfaceFormat::B8G8R8A8;
-    case ImageFormat::A8:
+    case ImageFormat::R8:
       return gfx::SurfaceFormat::A8;
     default:
       return gfx::SurfaceFormat::UNKNOWN;
   }
 }
 
 struct ImageDescriptor: public wr::WrImageDescriptor {
   // We need a default constructor for ipdl serialization.

--- a/gfx/webrender_bindings/webrender_ffi_generated.h
+++ b/gfx/webrender_bindings/webrender_ffi_generated.h
@@ -91,17 +91,17 @@ enum class FontRenderMode : uint32_t {
   Alpha = 1,
   Subpixel = 2,
 
   Sentinel /* this must be last for serialization purposes. */
 };
 
 enum class ImageFormat : uint32_t {
   Invalid = 0,
-  A8 = 1,
+  R8 = 1,
   BGRA8 = 3,
   RGBAF32 = 4,
   RG8 = 5,
 
   Sentinel /* this must be last for serialization purposes. */
 };
 
 enum class ImageRendering : uint32_t {