diff --git a/td/telegram/files/FileEncryptionKey.h b/td/telegram/files/FileEncryptionKey.h
index 039db2220..56433fd87 100644
--- a/td/telegram/files/FileEncryptionKey.h
+++ b/td/telegram/files/FileEncryptionKey.h
@@ -86,14 +86,15 @@ struct FileEncryptionKey {
     }
   }
 
+  friend bool operator==(const FileEncryptionKey &lhs, const FileEncryptionKey &rhs) {
+    return lhs.key_iv_ == rhs.key_iv_;
+  }
+
+ private:
   string key_iv_;  // TODO wrong alignment is possible
   Type type_ = Type::None;
 };
 
-inline bool operator==(const FileEncryptionKey &lhs, const FileEncryptionKey &rhs) {
-  return lhs.key_iv_ == rhs.key_iv_;
-}
-
 inline bool operator!=(const FileEncryptionKey &lhs, const FileEncryptionKey &rhs) {
   return !(lhs == rhs);
 }
diff --git a/td/telegram/files/FileManager.cpp b/td/telegram/files/FileManager.cpp
index 1859a2b48..469180a48 100644
--- a/td/telegram/files/FileManager.cpp
+++ b/td/telegram/files/FileManager.cpp
@@ -1278,7 +1278,7 @@ static int merge_choose_encryption_key(const FileEncryptionKey &a, const FileEnc
   if (a.empty() != b.empty()) {
     return a.empty() > b.empty();
   }
-  if (a.key_iv_ != b.key_iv_) {
+  if (a != b) {
     return -1;
   }
   return 2;