diff --git a/contracts/mocks/OwnableMock.sol b/contracts/mocks/OwnableMock.sol
index 97d6d5d25..8791b1b72 100644
--- a/contracts/mocks/OwnableMock.sol
+++ b/contracts/mocks/OwnableMock.sol
@@ -5,7 +5,6 @@ import { Ownable } from "../ownership/Ownable.sol";
 contract OwnableMock is Ownable {
 
   constructor() {
-    initialize();
+    Ownable.initialize();
   }
-
 }
diff --git a/contracts/token/ERC721/ERC721MetadataMintable.sol b/contracts/token/ERC721/ERC721MetadataMintable.sol
index caa401745..6c24c4478 100644
--- a/contracts/token/ERC721/ERC721MetadataMintable.sol
+++ b/contracts/token/ERC721/ERC721MetadataMintable.sol
@@ -11,6 +11,7 @@ import "../../access/roles/MinterRole.sol";
  */
 contract ERC721MetadataMintable is Initializable, ERC721, ERC721Metadata, MinterRole {
   function initialize() public initializer {
+    ERC721.initialize();
     MinterRole.initialize();
   }
 
diff --git a/contracts/token/ERC721/ERC721Mintable.sol b/contracts/token/ERC721/ERC721Mintable.sol
index 8a5c559df..34a09a48a 100644
--- a/contracts/token/ERC721/ERC721Mintable.sol
+++ b/contracts/token/ERC721/ERC721Mintable.sol
@@ -11,6 +11,7 @@ import "../../access/roles/MinterRole.sol";
  */
 contract ERC721Mintable is Initializable, ERC721, MinterRole {
   function initialize() public initializer {
+    ERC721.initialize();
     MinterRole.initialize();
   }