diff --git a/benchmark/bench_handshake.cpp b/benchmark/bench_handshake.cpp
index e57c78dbb..d56840a2c 100644
--- a/benchmark/bench_handshake.cpp
+++ b/benchmark/bench_handshake.cpp
@@ -6,6 +6,7 @@
 //
 #include "td/utils/benchmark.h"
 
+#include "td/mtproto/DhCallback.h"
 #include "td/mtproto/DhHandshake.h"
 
 #include "td/utils/base64.h"
diff --git a/td/mtproto/DhCallback.h b/td/mtproto/DhCallback.h
new file mode 100644
index 000000000..c26cd50e4
--- /dev/null
+++ b/td/mtproto/DhCallback.h
@@ -0,0 +1,29 @@
+//
+// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2021
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+#pragma once
+
+#include "td/utils/Slice.h"
+
+namespace td {
+namespace mtproto {
+
+class DhCallback {
+ public:
+  DhCallback() = default;
+  DhCallback(const DhCallback &) = delete;
+  DhCallback &operator=(const DhCallback &) = delete;
+  DhCallback(DhCallback &&) = delete;
+  DhCallback &operator=(DhCallback &&) = delete;
+  virtual ~DhCallback() = default;
+
+  virtual int is_good_prime(Slice prime_str) const = 0;
+  virtual void add_good_prime(Slice prime_str) const = 0;
+  virtual void add_bad_prime(Slice prime_str) const = 0;
+};
+
+}  // namespace mtproto
+}  // namespace td
diff --git a/td/mtproto/DhHandshake.cpp b/td/mtproto/DhHandshake.cpp
index 1b976c391..dfcdea28a 100644
--- a/td/mtproto/DhHandshake.cpp
+++ b/td/mtproto/DhHandshake.cpp
@@ -6,6 +6,8 @@
 //
 #include "td/mtproto/DhHandshake.h"
 
+#include "td/mtproto/DhCallback.h"
+
 #include "td/utils/as.h"
 #include "td/utils/crypto.h"
 #include "td/utils/logging.h"
diff --git a/td/mtproto/DhHandshake.h b/td/mtproto/DhHandshake.h
index 3bc7cea7a..8a2a24fc3 100644
--- a/td/mtproto/DhHandshake.h
+++ b/td/mtproto/DhHandshake.h
@@ -16,19 +16,7 @@
 namespace td {
 namespace mtproto {
 
-class DhCallback {
- public:
-  DhCallback() = default;
-  DhCallback(const DhCallback &) = delete;
-  DhCallback &operator=(const DhCallback &) = delete;
-  DhCallback(DhCallback &&) = delete;
-  DhCallback &operator=(DhCallback &&) = delete;
-  virtual ~DhCallback() = default;
-
-  virtual int is_good_prime(Slice prime_str) const = 0;
-  virtual void add_good_prime(Slice prime_str) const = 0;
-  virtual void add_bad_prime(Slice prime_str) const = 0;
-};
+class DhCallback;
 
 class DhHandshake {
  public:
diff --git a/td/mtproto/Handshake.cpp b/td/mtproto/Handshake.cpp
index 62d4be2e1..30d8ed5bc 100644
--- a/td/mtproto/Handshake.cpp
+++ b/td/mtproto/Handshake.cpp
@@ -6,6 +6,7 @@
 //
 #include "td/mtproto/Handshake.h"
 
+#include "td/mtproto/DhHandshake.h"
 #include "td/mtproto/KDF.h"
 #include "td/mtproto/mtproto_api.h"
 #include "td/mtproto/utils.h"
diff --git a/td/mtproto/Handshake.h b/td/mtproto/Handshake.h
index b09e345e2..ae94e8853 100644
--- a/td/mtproto/Handshake.h
+++ b/td/mtproto/Handshake.h
@@ -7,7 +7,6 @@
 #pragma once
 
 #include "td/mtproto/AuthKey.h"
-#include "td/mtproto/DhHandshake.h"
 #include "td/mtproto/RSA.h"
 
 #include "td/utils/buffer.h"
@@ -24,6 +23,8 @@ class Object;
 
 namespace mtproto {
 
+class DhCallback;
+
 class AuthKeyHandshakeContext {
  public:
   virtual ~AuthKeyHandshakeContext() = default;
diff --git a/td/telegram/DhCache.h b/td/telegram/DhCache.h
index 3e7310e20..a34c07d5a 100644
--- a/td/telegram/DhCache.h
+++ b/td/telegram/DhCache.h
@@ -6,7 +6,7 @@
 //
 #pragma once
 
-#include "td/mtproto/DhHandshake.h"
+#include "td/mtproto/DhCallback.h"
 
 #include "td/utils/Slice.h"
 
diff --git a/td/telegram/SecretChatActor.h b/td/telegram/SecretChatActor.h
index 846fefdaa..73905a52d 100644
--- a/td/telegram/SecretChatActor.h
+++ b/td/telegram/SecretChatActor.h
@@ -19,6 +19,7 @@
 #include "td/telegram/UserId.h"
 
 #include "td/mtproto/AuthKey.h"
+#include "td/mtproto/DhCallback.h"
 #include "td/mtproto/DhHandshake.h"
 
 #include "td/actor/actor.h"
diff --git a/td/telegram/SecretChatsManager.cpp b/td/telegram/SecretChatsManager.cpp
index 6c40929f7..1e1c1c13f 100644
--- a/td/telegram/SecretChatsManager.cpp
+++ b/td/telegram/SecretChatsManager.cpp
@@ -22,7 +22,7 @@
 #include "td/telegram/secret_api.h"
 #include "td/telegram/telegram_api.hpp"
 
-#include "td/mtproto/DhHandshake.h"
+#include "td/mtproto/DhCallback.h"
 
 #include "td/actor/PromiseFuture.h"
 
diff --git a/td/telegram/Td.cpp b/td/telegram/Td.cpp
index 5a1fc9035..c1909c50d 100644
--- a/td/telegram/Td.cpp
+++ b/td/telegram/Td.cpp
@@ -114,7 +114,7 @@
 
 #include "td/db/binlog/BinlogEvent.h"
 
-#include "td/mtproto/DhHandshake.h"
+#include "td/mtproto/DhCallback.h"
 #include "td/mtproto/Handshake.h"
 #include "td/mtproto/HandshakeActor.h"
 #include "td/mtproto/RawConnection.h"
diff --git a/td/telegram/net/Session.cpp b/td/telegram/net/Session.cpp
index 0c05a5b01..55ab6bd96 100644
--- a/td/telegram/net/Session.cpp
+++ b/td/telegram/net/Session.cpp
@@ -20,7 +20,7 @@
 #include "td/telegram/StateManager.h"
 #include "td/telegram/UniqueId.h"
 
-#include "td/mtproto/DhHandshake.h"
+#include "td/mtproto/DhCallback.h"
 #include "td/mtproto/Handshake.h"
 #include "td/mtproto/HandshakeActor.h"
 #include "td/mtproto/RawConnection.h"
diff --git a/test/mtproto.cpp b/test/mtproto.cpp
index 369ea7aea..85ce334a9 100644
--- a/test/mtproto.cpp
+++ b/test/mtproto.cpp
@@ -11,6 +11,7 @@
 #include "td/telegram/NotificationManager.h"
 
 #include "td/mtproto/AuthData.h"
+#include "td/mtproto/DhCallback.h"
 #include "td/mtproto/DhHandshake.h"
 #include "td/mtproto/Handshake.h"
 #include "td/mtproto/HandshakeActor.h"
diff --git a/test/secret.cpp b/test/secret.cpp
index 4bf32ddfc..db6794f3a 100644
--- a/test/secret.cpp
+++ b/test/secret.cpp
@@ -22,7 +22,7 @@
 #include "td/db/BinlogKeyValue.h"
 #include "td/db/DbKey.h"
 
-#include "td/mtproto/DhHandshake.h"
+#include "td/mtproto/DhCallback.h"
 #include "td/mtproto/utils.h"
 
 #include "td/tl/tl_object_parse.h"