diff --git a/requirements.txt b/requirements.txt
index 30f0d587..565eb51e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,6 +4,6 @@ prompt_toolkit==3.0.39
 pyfiglet==1.0.0
 pygments==2.16.1
 requests==2.31.0
-safe-eth-py==6.0.0a1
+safe-eth-py==6.0.0b2
 tabulate==0.9.0
 web3==6.10.0
diff --git a/safe_cli/operators/safe_operator.py b/safe_cli/operators/safe_operator.py
index 160e3ce8..f368aebc 100644
--- a/safe_cli/operators/safe_operator.py
+++ b/safe_cli/operators/safe_operator.py
@@ -512,7 +512,6 @@ def change_guard(self, guard: str) -> bool:
                 return True
 
     def change_master_copy(self, new_master_copy: str) -> bool:
-        # TODO Check that master copy is valid
         if new_master_copy == self.safe_cli_info.master_copy:
             raise SameMasterCopyException(new_master_copy)
         else:
diff --git a/tests/safe_cli_test_case_mixin.py b/tests/safe_cli_test_case_mixin.py
index a1429fd3..fbcb9d7d 100644
--- a/tests/safe_cli_test_case_mixin.py
+++ b/tests/safe_cli_test_case_mixin.py
@@ -8,7 +8,11 @@
 class SafeCliTestCaseMixin(SafeTestCaseMixin):
     def setup_operator(self, number_owners: int = 1, version="1.4.1") -> SafeOperator:
         assert number_owners >= 1, "Number of owners cannot be less than 1!"
-        if version == "1.1.1":
+        if version == "1.0.0":
+            safe = self.deploy_test_safe_v1_0_0(
+                owners=[self.ethereum_test_account.address]
+            )
+        elif version == "1.1.1":
             safe = self.deploy_test_safe_v1_1_1(
                 owners=[self.ethereum_test_account.address]
             )
diff --git a/tests/test_safe_operator.py b/tests/test_safe_operator.py
index 1f948a64..d8765f0e 100644
--- a/tests/test_safe_operator.py
+++ b/tests/test_safe_operator.py
@@ -144,9 +144,8 @@ def test_change_fallback_handler(self):
             safe_operator.change_fallback_handler(current_fallback_handler)
 
         new_fallback_handler = Account.create().address
-        with self.assertRaises(
-            InvalidFallbackHandlerException
-        ):  # Contract does not exist
+        with self.assertRaises(InvalidFallbackHandlerException):
+            # Contract does not exist
             self.assertTrue(safe_operator.change_fallback_handler(new_fallback_handler))
 
         with mock.patch.object(
@@ -158,9 +157,10 @@ def test_change_fallback_handler(self):
         )
         self.assertEqual(safe.retrieve_fallback_handler(), new_fallback_handler)
 
-        safe_operator.change_master_copy(self.safe_contract_V1_1_1.address)
+        # Safes < 1.1.0 don't support the fallback handler
+        safe_operator_v1_0_0 = self.setup_operator(version="1.0.0")
         with self.assertRaises(FallbackHandlerNotSupportedException):
-            safe_operator.change_fallback_handler(Account.create().address)
+            safe_operator_v1_0_0.change_fallback_handler(Account.create().address)
 
     def test_change_guard(self):
         safe_operator = self.setup_operator(version="1.1.1")
@@ -173,21 +173,20 @@ def test_change_guard(self):
         with self.assertRaises(SameGuardException):
             safe_operator.change_guard(current_guard)
 
-        new_guard = Account.create().address
+        not_valid_guard = Account.create().address
         with self.assertRaises(InvalidGuardException):  # Contract does not exist
-            self.assertTrue(safe_operator.change_guard(new_guard))
+            self.assertTrue(safe_operator.change_guard(not_valid_guard))
 
-        with mock.patch.object(
-            EthereumClient, "is_contract", autospec=True, return_value=True
-        ):
-            self.assertTrue(safe_operator.change_guard(new_guard))
+        new_guard = self.deploy_example_guard()
+        self.assertTrue(safe_operator.change_guard(new_guard))
         self.assertEqual(safe_operator.safe_cli_info.guard, new_guard)
         self.assertEqual(safe.retrieve_guard(), new_guard)
 
     def test_change_master_copy(self):
-        safe_operator = self.setup_operator()
+        safe_operator = self.setup_operator(version="1.1.1")
         safe = Safe(safe_operator.address, self.ethereum_client)
         current_master_copy = safe.retrieve_master_copy_address()
+        self.assertEqual(current_master_copy, self.safe_contract_V1_1_1.address)
         with self.assertRaises(SameMasterCopyException):
             safe_operator.change_master_copy(current_master_copy)
 
@@ -195,15 +194,10 @@ def test_change_master_copy(self):
         with self.assertRaises(InvalidMasterCopyException):
             safe_operator.change_master_copy(random_address)
 
-        self.assertTrue(
-            safe_operator.change_master_copy(self.safe_contract_V1_1_1.address)
-        )
-        self.assertEqual(
-            safe_operator.safe_cli_info.master_copy, self.safe_contract_V1_1_1.address
-        )
-        self.assertEqual(
-            safe.retrieve_master_copy_address(), self.safe_contract_V1_1_1.address
-        )
+        new_master_copy = self.safe_contract_V1_3_0.address
+        self.assertTrue(safe_operator.change_master_copy(new_master_copy))
+        self.assertEqual(safe_operator.safe_cli_info.master_copy, new_master_copy)
+        self.assertEqual(safe.retrieve_master_copy_address(), new_master_copy)
 
     def test_send_ether(self):
         safe_operator = self.setup_operator()