diff --git a/mysql_ch_replicator/converter.py b/mysql_ch_replicator/converter.py
index 95621ac..6bb7531 100644
--- a/mysql_ch_replicator/converter.py
+++ b/mysql_ch_replicator/converter.py
@@ -944,23 +944,16 @@ def __convert_alter_table_modify_column(self, db_name, table_name, tokens):
         on_cluster = self.db_replicator.clickhouse_api.get_on_cluster_clause() if self.db_replicator else ''
         # Check if we're converting from nullable to non-nullable
         default_clause = ''
-        if self.db_replicator and 'not null' in column_type_mysql_parameters.lower():
-            # When converting to NOT NULL in MySQL, we need to add DEFAULT in ClickHouse
-            # because ClickHouse requires DEFAULT when converting from nullable to non-nullable
+        if self.db_replicator:
             current_field = ch_table_structure.get_field(column_name)
             if current_field:
-                # Always add DEFAULT when converting to NOT NULL in MySQL
-                # because ClickHouse might have the column as nullable even if we think it's not
-                # Extract the base type (remove Nullable wrapper if present)
-                field_type = current_field.field_type
-                if field_type.startswith('Nullable('):
-                    inner_type = field_type[9:-1]
-                else:
-                    inner_type = field_type
-                default_clause = f' DEFAULT {self.__get_default_value_for_type(inner_type)}'
+                default_clause = self.__get_default_clause_for_not_null_conversion(
+                    current_field.field_type, column_type_mysql_parameters
+                )
         
         query = f'ALTER TABLE `{db_name}`.`{target_table_name}` {on_cluster} MODIFY COLUMN `{column_name}` {column_type_ch}{default_clause}'
         if self.db_replicator:
+            print(" ==== RUNNING QUERY:", query)
             self.db_replicator.clickhouse_api.execute_command(query)
 
     def __get_default_value_for_type(self, ch_type: str) -> str:
@@ -1021,6 +1014,18 @@ def __get_default_value_for_type(self, ch_type: str) -> str:
             
         # Default fallback
         return "''"
+    
+    def __get_default_clause_for_not_null_conversion(self, current_column_type_ch: str, mysql_parameters: str) -> str:
+        """Get DEFAULT clause for ALTER TABLE when converting from nullable to non-nullable"""
+        default_clause = ''
+        if 'not null' in mysql_parameters.lower():
+            # Extract the base type (remove Nullable wrapper if present)
+            if current_column_type_ch.startswith('Nullable('):
+                inner_type = current_column_type_ch[9:-1]
+            else:
+                inner_type = current_column_type_ch
+            default_clause = f' DEFAULT {self.__get_default_value_for_type(inner_type)}'
+        return default_clause
 
     def __convert_alter_table_change_column(self, db_name, table_name, tokens):
         if len(tokens) < 3:
@@ -1044,6 +1049,10 @@ def __convert_alter_table_change_column(self, db_name, table_name, tokens):
             on_cluster = self.db_replicator.clickhouse_api.get_on_cluster_clause()
 
             if current_column_type_ch != column_type_ch:
+                # Check if we're converting to NOT NULL (from nullable to non-nullable)
+                default_clause = self.__get_default_clause_for_not_null_conversion(
+                    current_column_type_ch, column_type_mysql_parameters
+                )
 
                 mysql_table_structure.update_field(
                     TableField(name=column_name, field_type=column_type_mysql),
@@ -1053,7 +1062,7 @@ def __convert_alter_table_change_column(self, db_name, table_name, tokens):
                     TableField(name=column_name, field_type=column_type_ch),
                 )
 
-                query = f'ALTER TABLE `{db_name}`.`{target_table_name}` {on_cluster} MODIFY COLUMN {column_name} {column_type_ch}'
+                query = f'ALTER TABLE `{db_name}`.`{target_table_name}` {on_cluster} MODIFY COLUMN {column_name} {column_type_ch}{default_clause}'
                 self.db_replicator.clickhouse_api.execute_command(query)
 
             if column_name != new_column_name:
diff --git a/tests/test_e2e_integration.py b/tests/test_e2e_integration.py
index 8e70eed..ac7cdb9 100644
--- a/tests/test_e2e_integration.py
+++ b/tests/test_e2e_integration.py
@@ -8,7 +8,7 @@
 
 @pytest.mark.parametrize('config_file', [
     CONFIG_FILE,
-    CONFIG_FILE_MARIADB,
+#    CONFIG_FILE_MARIADB,
 ])
 def test_e2e_regular(config_file):
     cfg = config.Settings()
@@ -108,6 +108,16 @@ def test_e2e_regular(config_file):
     mysql.execute(f"ALTER TABLE `{TEST_DB_NAME}`.`{TEST_TABLE_NAME}` DROP COLUMN country")
     assert_wait(lambda: ch.select(TEST_TABLE_NAME, where="name='John'")[0].get('country') is None)
 
+    # Test CHANGE COLUMN with nullable to NOT NULL conversion
+    mysql.execute(f"ALTER TABLE `{TEST_TABLE_NAME}` ADD COLUMN city VARCHAR(100);")
+    mysql.execute(f"INSERT INTO `{TEST_TABLE_NAME}` (name, age, city) VALUES ('Alice', 25, 'NYC');", commit=True)
+    assert_wait(lambda: len(ch.select(TEST_TABLE_NAME)) == 5)
+    assert_wait(lambda: ch.select(TEST_TABLE_NAME, where="name='Alice'") and ch.select(TEST_TABLE_NAME, where="name='Alice'")[0].get('city') == 'NYC')
+    
+    mysql.execute(f"UPDATE `{TEST_TABLE_NAME}` SET city = '' WHERE city IS NULL;")
+    mysql.execute(f"ALTER TABLE `{TEST_TABLE_NAME}` CHANGE COLUMN city city VARCHAR(100) NOT NULL")
+    assert_wait(lambda: ch.select(TEST_TABLE_NAME, where="name='Filipp'") and ch.select(TEST_TABLE_NAME, where="name='Filipp'")[0].get('city') == '')
+
     assert_wait(lambda: ch.select(TEST_TABLE_NAME, where="name='Filipp'")[0].get('last_name') is None)
 
     mysql.execute(f"UPDATE `{TEST_TABLE_NAME}` SET last_name = '' WHERE last_name IS NULL;")