diff --git a/qutebrowser/completion/models/configmodel.py b/qutebrowser/completion/models/configmodel.py
index 84f5d24f3..48e649007 100644
--- a/qutebrowser/completion/models/configmodel.py
+++ b/qutebrowser/completion/models/configmodel.py
@@ -20,8 +20,7 @@
 """Functions that return config-related completion models."""
 
 from qutebrowser.config import configdata, configexc, config
-from qutebrowser.completion.models import completionmodel, listcategory
-from qutebrowser.utils import objreg
+from qutebrowser.completion.models import completionmodel, listcategory, util
 from qutebrowser.commands import cmdutils
 
 
@@ -34,12 +33,12 @@ def option():
     return model
 
 
-def value(optname, *values):
+def value(optname, *_values):
     """A CompletionModel filled with setting values.
 
     Args:
         optname: The name of the config option this model shows.
-        values: The values already provided on the command line.
+        _values: The values already provided on the command line.
     """
     model = completionmodel.CompletionModel(column_widths=(30, 70, 0))
 
diff --git a/qutebrowser/completion/models/histcategory.py b/qutebrowser/completion/models/histcategory.py
index 426cf907c..b993b40de 100644
--- a/qutebrowser/completion/models/histcategory.py
+++ b/qutebrowser/completion/models/histcategory.py
@@ -38,9 +38,9 @@ class HistoryCategory(QSqlQueryModel):
         self.name = "History"
 
         # replace ' in timestamp-format to avoid breaking the query
+        timestamp_format = config.val.completion.timestamp_format
         timefmt = ("strftime('{}', last_atime, 'unixepoch', 'localtime')"
-                   .format(config.val.completion.timestamp_format
-                           .replace("'", "`")))
+                   .format(timestamp_format.replace("'", "`")))
 
         self._query = sql.Query(' '.join([
             "SELECT url, title, {}".format(timefmt),
diff --git a/qutebrowser/config/configexc.py b/qutebrowser/config/configexc.py
index 8293e5fe1..6bebc55e7 100644
--- a/qutebrowser/config/configexc.py
+++ b/qutebrowser/config/configexc.py
@@ -41,14 +41,12 @@ class ValidationError(Error):
     """Raised when a value for a config type was invalid.
 
     Attributes:
-        section: Section in which the error occurred (added when catching and
-                 re-raising the exception).
-        option: Option in which the error occurred.
+        value: Config value that triggered the error.
+        msg: Additional error message.
     """
 
     def __init__(self, value, msg):
         super().__init__("Invalid value '{}' - {}".format(value, msg))
-        self.section = None
         self.option = None
 
 
diff --git a/scripts/dev/run_vulture.py b/scripts/dev/run_vulture.py
index 4a31c56c1..9568603fd 100755
--- a/scripts/dev/run_vulture.py
+++ b/scripts/dev/run_vulture.py
@@ -78,8 +78,7 @@ def whitelist_generator():
         yield 'qutebrowser.browser.qutescheme.qute_' + name
 
     # Other false-positives
-    yield ('qutebrowser.completion.models.sortfilter.CompletionFilterModel().'
-           'lessThan')
+    yield 'qutebrowser.completion.models.listcategory.ListCategory().lessThan'
     yield 'qutebrowser.utils.jinja.Loader.get_source'
     yield 'qutebrowser.utils.log.QtWarningFilter.filter'
     yield 'qutebrowser.browser.pdfjs.is_available'
@@ -107,12 +106,6 @@ def whitelist_generator():
     for name, member in inspect.getmembers(configtypes, inspect.isclass):
         yield 'qutebrowser.config.configtypes.' + name
 
-    ### FIXME:conf
-    ## completion
-    for name in ['Section', 'Option', 'Value']:
-        klass = 'Setting{}CompletionModel'.format(name)
-        yield 'qutebrowser.completion.models.configmodel.' + klass
-    # in qutebrowser.completion.models.miscmodels._get_cmd_completions
     yield 'include_aliases'
     ## FIXME:conf TODO
     yield 'qutebrowser.config.configdata.DEFAULT_FONT_SIZE'
diff --git a/tests/unit/completion/test_models.py b/tests/unit/completion/test_models.py
index 25468be95..1945f53ec 100644
--- a/tests/unit/completion/test_models.py
+++ b/tests/unit/completion/test_models.py
@@ -18,7 +18,6 @@
 # along with qutebrowser.  If not, see <http://www.gnu.org/licenses/>.
 
 # FIXME:conf
-# pylint: disable=undefined-variable
 
 """Tests for completion models."""
 
diff --git a/tests/unit/config/test_configexc.py b/tests/unit/config/test_configexc.py
index 5da3837c1..8a46b9cda 100644
--- a/tests/unit/config/test_configexc.py
+++ b/tests/unit/config/test_configexc.py
@@ -24,7 +24,6 @@ from qutebrowser.utils import usertypes
 
 def test_validation_error():
     e = configexc.ValidationError('val', 'msg')
-    assert e.section is None
     assert e.option is None
     assert str(e) == "Invalid value 'val' - msg"