diff --git a/graphene_django/converter.py b/graphene_django/converter.py
index 4d0b45f95..191a2c3d4 100644
--- a/graphene_django/converter.py
+++ b/graphene_django/converter.py
@@ -28,8 +28,31 @@
 singledispatch = import_single_dispatch()
 
 
+def _is_dunder(name):
+    """Returns True if a __dunder__ name, False otherwise."""
+    return (
+        len(name) > 4
+        and name[:2] == name[-2:] == "__"
+        and name[2:3] != "_"
+        and name[-3:-2] != "_"
+    )
+
+
+def _is_sunder(name):
+    """Returns True if a _sunder_ name, False otherwise."""
+    return (
+        len(name) > 2
+        and name[0] == name[-1] == "_"
+        and name[1:2] != "_"
+        and name[-2:-1] != "_"
+    )
+
+
 def convert_choice_name(name):
-    name = to_const(force_text(name))
+    name = force_text(name).encode("utf8").decode("ascii", "ignore")
+    name = to_const(name)
+    if _is_sunder(name) or _is_dunder(name):
+        name = "A%s" % name
     try:
         assert_valid_name(name)
     except AssertionError:
diff --git a/graphene_django/tests/models.py b/graphene_django/tests/models.py
index b4eb3ce8a..f7a4cf0f3 100644
--- a/graphene_django/tests/models.py
+++ b/graphene_django/tests/models.py
@@ -1,9 +1,16 @@
+# -*- coding: utf-8 -*-
 from __future__ import absolute_import
 
 from django.db import models
 from django.utils.translation import ugettext_lazy as _
 
-CHOICES = ((1, "this"), (2, _("that")))
+CHOICES = (
+    (1, u"this"),
+    ("2", _(u"that")),
+    (u"_3漢", "nonascii"),
+    ("__dunder__", "dunder"),
+    ("_sunder_", "sunder"),
+)
 
 
 class Pet(models.Model):
diff --git a/graphene_django/tests/test_converter.py b/graphene_django/tests/test_converter.py
index 5542c90a7..9ea8dc919 100644
--- a/graphene_django/tests/test_converter.py
+++ b/graphene_django/tests/test_converter.py
@@ -196,6 +196,27 @@ class Meta:
     convert_django_field_with_choices(field)
 
 
+def test_field_with_choices_underscore():
+    field = models.CharField(
+        choices=(
+            ("_amount_", "Amount"),
+            ("__percentage__", "Percentage"),
+            ("_not_sunder__", "Not Single Underscore"),
+            ("__not_dunder", "Not Double Underscore"),
+        )
+    )
+
+    class UnderscoreChoicesModel(models.Model):
+        ourfield = field
+
+    graphene_type = convert_django_field_with_choices(field)
+    assert len(graphene_type._meta.enum.__members__) == 4
+    assert "A_AMOUNT_" in graphene_type._meta.enum.__members__
+    assert "A__PERCENTAGE__" in graphene_type._meta.enum.__members__
+    assert "_NOT_SUNDER__" in graphene_type._meta.enum.__members__
+    assert "__NOT_DUNDER" in graphene_type._meta.enum.__members__
+
+
 def test_field_with_choices_convert_enum_false():
     field = models.CharField(
         help_text="Language", choices=(("es", "Spanish"), ("en", "English"))
diff --git a/graphene_django/tests/test_types.py b/graphene_django/tests/test_types.py
index c1ac6c2bc..3dd0c618b 100644
--- a/graphene_django/tests/test_types.py
+++ b/graphene_django/tests/test_types.py
@@ -179,6 +179,9 @@ def test_schema_representation():
 enum ReporterAChoice {
   A_1
   A_2
+  _3
+  A__DUNDER__
+  A_SUNDER_
 }
 
 enum ReporterReporterType {