diff --git a/clang/lib/AST/Interp/Pointer.h b/clang/lib/AST/Interp/Pointer.h
index f8e3802d4a229..8385b032c207b 100644
--- a/clang/lib/AST/Interp/Pointer.h
+++ b/clang/lib/AST/Interp/Pointer.h
@@ -29,6 +29,9 @@ class DeadBlock;
 class Pointer;
 enum PrimType : unsigned;
 
+class Pointer;
+inline llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, const Pointer &P);
+
 /// A pointer to a memory block, live or dead.
 ///
 /// This object can be allocated into interpreter stack frames. If pointing to