diff --git a/mashumaro/core/meta/code/builder.py b/mashumaro/core/meta/code/builder.py
index e4fbb27f..0292ebbc 100644
--- a/mashumaro/core/meta/code/builder.py
+++ b/mashumaro/core/meta/code/builder.py
@@ -1,3 +1,4 @@
+import enum
 import importlib
 import inspect
 import math
@@ -1209,7 +1210,9 @@ def get_dialect_or_config_option(
         return default
 
     def get_field_default_literal(self, value: typing.Any) -> str:
-        if isinstance(value, (str, int, bool, NoneType)):  # type: ignore
+        if isinstance(value, enum.IntFlag):
+            return str(value.value)
+        elif isinstance(value, (str, int, bool, NoneType)):  # type: ignore
             return repr(value)
         elif (
             isinstance(value, float)
diff --git a/tests/test_data_types.py b/tests/test_data_types.py
index ac164a04..40da798a 100644
--- a/tests/test_data_types.py
+++ b/tests/test_data_types.py
@@ -1503,6 +1503,19 @@ class Config(BaseConfig):
     }
 
 
+def test_dataclass_with_default_int_flag_omit_default():
+    @dataclass
+    class DataClass(DataClassDictMixin):
+        a: MyIntFlag = MyIntFlag.a
+        b: MyIntFlag = MyIntFlag.b
+
+        class Config(BaseConfig):
+            omit_default = True
+
+    assert DataClass().to_dict() == {}
+    assert DataClass(MyIntFlag.a, MyIntFlag.b).to_dict() == {}
+
+
 @pytest.mark.parametrize("value_info", inner_values)
 def test_decoder(value_info):
     x_type, x_value, x_value_dumped = value_info