diff --git a/tests/test_formdata.py b/tests/test_formdata.py
index d0f825954..980f12045 100644
--- a/tests/test_formdata.py
+++ b/tests/test_formdata.py
@@ -9,7 +9,7 @@ import pytest
 from quixote import get_publisher
 from quixote.http_request import Upload
 
-from wcs import fields, formdef, sessions
+from wcs import fields, sessions
 from wcs.blocks import BlockDef
 from wcs.carddef import CardDef
 from wcs.categories import Category
@@ -49,21 +49,20 @@ def pub(request):
     pub.cfg['language'] = {'language': 'en'}
     pub.write_cfg()
 
+    return pub
+
+
+@pytest.fixture
+def formdef(pub):
     FormDef.wipe()
-    Category.wipe()
 
-    cat = Category(name='test category')
-    cat.store()
-
-    global formdef
     formdef = FormDef()
     formdef.name = 'foobar'
     formdef.url_name = 'foobar'
     formdef.fields = []
-    formdef.category_id = cat.id
     formdef.store()
 
-    return pub
+    return formdef
 
 
 def teardown_module(module):
@@ -81,7 +80,12 @@ def local_user():
     return user
 
 
-def test_basic(pub):
+def test_basic(pub, formdef):
+    Category.wipe()
+    cat = Category(name='test category')
+    cat.store()
+    formdef.category_id = cat.id
+    formdef.store()
     formdata = formdef.data_class()()
     substvars = formdata.get_substitution_variables()
     assert substvars.get('form_status') == 'Unknown'
@@ -90,7 +94,7 @@ def test_basic(pub):
     assert substvars.get('category_name') == 'test category'
 
 
-def test_saved(pub):
+def test_saved(pub, formdef):
     formdef.data_class().wipe()
     formdata = formdef.data_class()()
     formdata.store()
@@ -102,7 +106,7 @@ def test_saved(pub):
     assert substvars.get('form_status_url').endswith('/foobar/1/status')
 
 
-def test_auto_display_id(pub):
+def test_auto_display_id(pub, formdef):
     formdef.data_class().wipe()
     formdata = formdef.data_class()()
     formdata.store()
@@ -111,7 +115,7 @@ def test_auto_display_id(pub):
     assert substvars.get('form_number_raw') == str(formdata.id)
 
 
-def test_manual_display_id(pub):
+def test_manual_display_id(pub, formdef):
     formdef.data_class().wipe()
     formdata = formdef.data_class()()
     formdata.id_display = 'bar'
@@ -121,7 +125,7 @@ def test_manual_display_id(pub):
     assert substvars.get('form_number_raw') == str(formdata.id)
 
 
-def test_submission_context(pub, local_user):
+def test_submission_context(pub, formdef, local_user):
     formdef.data_class().wipe()
     formdata = formdef.data_class()()
     formdata.backoffice_submission = True
@@ -145,7 +149,7 @@ def test_submission_context(pub, local_user):
     assert substvars.get('form_submission_agent_email') is None
 
 
-def test_just_created(pub):
+def test_just_created(pub, formdef):
     formdef.data_class().wipe()
     formdata = formdef.data_class()()
     formdata.just_created()
@@ -160,7 +164,7 @@ def test_just_created(pub):
     assert substvars.get('form_evolution')
 
 
-def test_field(pub):
+def test_field(pub, formdef):
     formdef.data_class().wipe()
     formdef.fields = [fields.StringField(id='0', label='string')]
     formdef.store()
@@ -174,7 +178,7 @@ def test_field(pub):
     assert substvars.get('form_field_string') == 'test'
 
 
-def test_field_varname(pub):
+def test_field_varname(pub, formdef):
     formdef.data_class().wipe()
     formdef.fields = [fields.StringField(id='0', label='string', varname='foo')]
     formdef.store()
@@ -185,7 +189,7 @@ def test_field_varname(pub):
     assert substvars.get('form_var_foo') == 'test'
 
 
-def test_file_field(pub):
+def test_file_field(pub, formdef):
     formdef.data_class().wipe()
     formdef.fields = [fields.FileField(id='0', label='file', varname='foo')]
     formdef.store()
@@ -212,7 +216,7 @@ def test_file_field(pub):
     assert substvars['form_var_foo_url'] is None
 
 
-def test_get_submitter(pub):
+def test_get_submitter(pub, formdef):
     formdef.data_class().wipe()
     formdef.fields = [
         fields.StringField(id='0', label='email', varname='foo', prefill={'type': 'user', 'value': 'email'})
@@ -235,9 +239,8 @@ def test_get_submitter(pub):
     assert formdef.get_submitter_email(formdata) == 'bar@localhost'
 
 
-def test_get_last_update_time(pub):
+def test_get_last_update_time(pub, formdef):
     formdef.data_class().wipe()
-    formdef.store()
 
     formdata = formdef.data_class()()
     assert formdata.last_update_time is None
@@ -259,7 +262,7 @@ def test_get_last_update_time(pub):
     assert formdata.last_update_time == formdata.receipt_time
 
 
-def test_password_field(pub):
+def test_password_field(pub, formdef):
     formdef.data_class().wipe()
     formdef.fields = [fields.PasswordField(id='0', label='pwd')]
     formdef.store()
@@ -271,7 +274,7 @@ def test_password_field(pub):
     assert formdata2.data == {'0': {'cleartext': 'foo'}}
 
 
-def test_date_field(pub):
+def test_date_field(pub, formdef):
     formdef.data_class().wipe()
     formdef.fields = [fields.DateField(id='0', label='date')]
     formdef.store()
@@ -507,7 +510,7 @@ def test_field_bool_substvars(pub):
     assert variables.get('form_var_xxx_raw') is True
 
 
-def test_backoffice_field_varname(pub):
+def test_backoffice_field_varname(pub, formdef):
     wf = Workflow(name='bo fields')
     wf.backoffice_fields_formdef = WorkflowBackofficeFieldsFormDef(wf)
     wf.backoffice_fields_formdef.fields = [
@@ -526,7 +529,7 @@ def test_backoffice_field_varname(pub):
     assert substvars.get('form_var_backoffice_blah') == 'test'
 
 
-def test_workflow_data_file_url(pub):
+def test_workflow_data_file_url(pub, formdef):
     upload = PicklableUpload('test.txt', 'text/plain', 'ascii')
     upload.receive([b'first line', b'second line'])
 
diff --git a/tests/test_sql.py b/tests/test_sql.py
index 71aca8784..64682b64b 100644
--- a/tests/test_sql.py
+++ b/tests/test_sql.py
@@ -575,7 +575,6 @@ def test_get_users_formdef_fts():
 
 @postgresql
 def test_urlname_change():
-    global formef
     data_class = formdef.data_class(mode='sql')
     data_class.wipe()
     assert formdef.url_name == 'tests'