diff --git a/query_exporter/config.py b/query_exporter/config.py
index 9db1234..0014330 100644
--- a/query_exporter/config.py
+++ b/query_exporter/config.py
@@ -1,7 +1,7 @@
 """Configuration management functions."""
 
 from collections import defaultdict
-from collections.abc import Mapping
+from collections.abc import Iterable, Mapping
 from dataclasses import dataclass
 from functools import reduce
 from importlib import resources
@@ -245,7 +245,7 @@ def _get_query_metrics(
 ) -> list[QueryMetric]:
     """Return QueryMetrics for a query."""
 
-    def _metric_labels(labels: list[str]) -> list[str]:
+    def _metric_labels(labels: Iterable[str]) -> list[str]:
         return sorted(set(labels) - extra_labels)
 
     return [
diff --git a/query_exporter/loop.py b/query_exporter/loop.py
index 75b025b..0b75078 100644
--- a/query_exporter/loop.py
+++ b/query_exporter/loop.py
@@ -255,7 +255,7 @@ def _update_metric(
             value = 0.0
         elif isinstance(value, Decimal):
             value = float(value)
-        metric = self._config.metrics[name]
+        metric_config = self._config.metrics[name]
         all_labels = {DATABASE_LABEL: database.config.name}
         all_labels.update(database.config.labels)
         if labels:
@@ -263,7 +263,7 @@ def _update_metric(
         labels_string = ",".join(
             f'{label}="{value}"' for label, value in sorted(all_labels.items())
         )
-        method = self._get_metric_method(metric)
+        method = self._get_metric_method(metric_config)
         self._logger.debug(
             f'updating metric "{name}" {method} {value} {{{labels_string}}}'
         )
diff --git a/query_exporter/main.py b/query_exporter/main.py
index a71acd4..71f9efa 100644
--- a/query_exporter/main.py
+++ b/query_exporter/main.py
@@ -22,7 +22,7 @@
 from .loop import QueryLoop
 
 
-class QueryExporterScript(PrometheusExporterScript):  # type: ignore
+class QueryExporterScript(PrometheusExporterScript):
     """Periodically run database queries and export results to Prometheus."""
 
     name = "query-exporter"