diff --git a/renderdoc/driver/metal/official/metal-cpp.h b/renderdoc/driver/metal/official/metal-cpp.h
index 1bf7e3534..a7eb9a76d 100644
--- a/renderdoc/driver/metal/official/metal-cpp.h
+++ b/renderdoc/driver/metal/official/metal-cpp.h
@@ -4511,6 +4511,7 @@ _MTL_PRIVATE_DEF_SEL(writeMask,
 
 namespace MTL
 {
+class Drawable;
 using DrawablePresentedHandler = void (^)(class Drawable*);
 
 using DrawablePresentedHandlerFunction = std::function<void(class Drawable*)>;