diff --git a/renderdoc/driver/metal/metal_types.h b/renderdoc/driver/metal/metal_types.h
index 9324ecbab..6e284ccbc 100644
--- a/renderdoc/driver/metal/metal_types.h
+++ b/renderdoc/driver/metal/metal_types.h
@@ -33,8 +33,12 @@
   FUNC(Function);                        \
   FUNC(Library);
 
-#define DECLARE_OBJC_HELPERS(CPPTYPE) \
-  class WrappedMTL##CPPTYPE;          \
+#define DECLARE_OBJC_HELPERS(CPPTYPE)                                \
+  class WrappedMTL##CPPTYPE;                                         \
+  extern WrappedMTL##CPPTYPE *GetWrapped(MTL::CPPTYPE *objCWrapped); \
+  extern MTL::CPPTYPE *GetReal(MTL::CPPTYPE *objCWrapped);           \
+  extern bool IsObjCWrapped(MTL::CPPTYPE *objCWrapped);              \
+  extern ResourceId GetId(MTL::CPPTYPE *objCWrapped);                \
   extern MTL::CPPTYPE *AllocateObjCBridge(WrappedMTL##CPPTYPE *wrapped);
 
 METALCPP_WRAPPED_PROTOCOLS(DECLARE_OBJC_HELPERS)