diff --git a/hpb/extension.h b/hpb/extension.h
index 5ede3f5a60..d5fa632e31 100644
--- a/hpb/extension.h
+++ b/hpb/extension.h
@@ -16,6 +16,7 @@
 #include "google/protobuf/hpb/internal/message_lock.h"
 #include "google/protobuf/hpb/internal/template_help.h"
 #include "google/protobuf/hpb/ptr.h"
+#include "google/protobuf/hpb/status.h"
 #include "upb/mem/arena.hpp"
 #include "upb/mini_table/extension.h"
 #include "upb/mini_table/extension_registry.h"
@@ -205,6 +206,37 @@ absl::Status SetExtension(
   return ::hpb::SetExtension(Ptr(message), id, value);
 }
 
+template <typename T, typename Extendee, typename Extension,
+          typename = hpb::internal::EnableIfHpbClass<T>>
+absl::StatusOr<Ptr<const Extension>> GetExtension(
+    Ptr<T> message,
+    const ::hpb::internal::ExtensionIdentifier<Extendee, Extension>& id) {
+  upb_MessageValue value;
+  const bool ok = ::hpb::internal::GetOrPromoteExtension(
+      hpb::interop::upb::GetMessage(message), id.mini_table_ext(),
+      hpb::interop::upb::GetArena(message), &value);
+  if (!ok) {
+    return ExtensionNotFoundError(
+        upb_MiniTableExtension_Number(id.mini_table_ext()));
+  }
+  return Ptr<const Extension>(::hpb::interop::upb::MakeCHandle<Extension>(
+      (upb_Message*)value.msg_val, hpb::interop::upb::GetArena(message)));
+}
+
+template <typename T, typename Extendee, typename Extension,
+          typename = hpb::internal::EnableIfHpbClass<T>>
+absl::StatusOr<Ptr<const Extension>> GetExtension(
+    const T* message,
+    const ::hpb::internal::ExtensionIdentifier<Extendee, Extension>& id) {
+  return GetExtension(Ptr(message), id);
+}
+
+template <typename T, typename Extension>
+constexpr uint32_t ExtensionNumber(
+    ::hpb::internal::ExtensionIdentifier<T, Extension> id) {
+  return ::hpb::internal::PrivateAccess::GetExtensionNumber(id);
+}
+
 }  // namespace hpb
 
 #endif  // GOOGLE_PROTOBUF_HPB_EXTENSION_H__
diff --git a/hpb/hpb.h b/hpb/hpb.h
index 3bdec86824..fbd6ed2f75 100644
--- a/hpb/hpb.h
+++ b/hpb/hpb.h
@@ -36,37 +36,6 @@ namespace hpb {
 namespace backend = ::hpb::internal::backend::upb;
 #endif
 
-template <typename T, typename Extendee, typename Extension,
-          typename = hpb::internal::EnableIfHpbClass<T>>
-absl::StatusOr<Ptr<const Extension>> GetExtension(
-    Ptr<T> message,
-    const ::hpb::internal::ExtensionIdentifier<Extendee, Extension>& id) {
-  upb_MessageValue value;
-  const bool ok = ::hpb::internal::GetOrPromoteExtension(
-      hpb::interop::upb::GetMessage(message), id.mini_table_ext(),
-      hpb::interop::upb::GetArena(message), &value);
-  if (!ok) {
-    return ExtensionNotFoundError(
-        upb_MiniTableExtension_Number(id.mini_table_ext()));
-  }
-  return Ptr<const Extension>(::hpb::interop::upb::MakeCHandle<Extension>(
-      (upb_Message*)value.msg_val, hpb::interop::upb::GetArena(message)));
-}
-
-template <typename T, typename Extendee, typename Extension,
-          typename = hpb::internal::EnableIfHpbClass<T>>
-absl::StatusOr<Ptr<const Extension>> GetExtension(
-    const T* message,
-    const ::hpb::internal::ExtensionIdentifier<Extendee, Extension>& id) {
-  return GetExtension(Ptr(message), id);
-}
-
-template <typename T, typename Extension>
-constexpr uint32_t ExtensionNumber(
-    ::hpb::internal::ExtensionIdentifier<T, Extension> id) {
-  return ::hpb::internal::PrivateAccess::GetExtensionNumber(id);
-}
-
 template <typename T>
 typename T::Proxy CreateMessage(hpb::Arena& arena) {
   return typename T::Proxy(upb_Message_New(T::minitable(), arena.ptr()),