diff --git a/core/migrations/0035_auto_20200216_1743.py b/core/migrations/0035_auto_20200216_1743.py
new file mode 100644
index 00000000..07545832
--- /dev/null
+++ b/core/migrations/0035_auto_20200216_1743.py
@@ -0,0 +1,24 @@
+# Generated by Django 2.2.10 on 2020-02-16 16:43
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("core", "0034_operationlog"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="user",
+            name="sex",
+            field=models.CharField(
+                blank=True,
+                choices=[("MAN", "Man"), ("WOMAN", "Woman")],
+                max_length=10,
+                null=True,
+                verbose_name="sex",
+            ),
+        ),
+    ]
diff --git a/core/models.py b/core/models.py
index c51c9aab..afa24b9a 100644
--- a/core/models.py
+++ b/core/models.py
@@ -225,8 +225,9 @@ class User(AbstractBaseUser):
     sex = models.CharField(
         _("sex"),
         max_length=10,
+        null=True,
+        blank=True,
         choices=[("MAN", _("Man")), ("WOMAN", _("Woman"))],
-        default="MAN",
     )
     tshirt_size = models.CharField(
         _("tshirt size"),
diff --git a/matmat/templates/matmat/search_form.jinja b/matmat/templates/matmat/search_form.jinja
index 34d1c1a3..9a2eb149 100644
--- a/matmat/templates/matmat/search_form.jinja
+++ b/matmat/templates/matmat/search_form.jinja
@@ -43,7 +43,6 @@
     {{ form.phone.errors }}
     <label for="{{ form.phone.id_for_label }}">{{ form.phone.label }}</label>
     {{ form.phone }}
-    {{ form.sex.as_hidden() }}
     <p><input type="submit" value="{% trans %}Search{% endtrans %}" /></p>
     </p>
 </form>
@@ -53,7 +52,6 @@
     <p>
         {{ form.quick.errors }}
         <label for="{{ form.quick.id_for_label }}">{{ form.quick.label }}</label>
-        {{ form.sex.as_hidden() }}
         {{ form.quick }}
         <p><input type="submit" value="{% trans %}Search{% endtrans %}" /></p>
     </p>
diff --git a/matmat/views.py b/matmat/views.py
index 112c1d54..a2d8fff9 100644
--- a/matmat/views.py
+++ b/matmat/views.py
@@ -69,17 +69,6 @@ class SearchForm(forms.ModelForm):
             "phone": PhoneNumberInternationalFallbackWidget,
         }
 
-    sex = forms.ChoiceField(
-        choices=[
-            ("MAN", _("Man")),
-            ("WOMAN", _("Woman")),
-            ("INDIFFERENT", _("Indifferent")),
-        ],
-        widget=forms.RadioSelect,
-        initial="INDIFFERENT",
-        label=_("Sex"),
-    )
-
     quick = forms.CharField(label=_("Last/First name or nickname"), max_length=255)
 
     def __init__(self, *args, **kwargs):
@@ -150,7 +139,7 @@ class SearchFormListView(FormerSubscriberMixin, SingleObjectMixin, ListView):
                 search_dict = {}
                 for key, value in self.valid_form.items():
                     if key not in ("phone", "quick") and not (
-                        value == "" or value is None or value == "INDIFFERENT"
+                        value == "" or value is None
                     ):
                         search_dict[key + "__icontains"] = value
                 q = q.filter(**search_dict).all()