diff --git a/fence/metrics.py b/fence/metrics.py
index ad82e0abc..0f60e8654 100644
--- a/fence/metrics.py
+++ b/fence/metrics.py
@@ -14,7 +14,6 @@
 
 class Metrics:
     def __init__(self):
-        self.app = None
         self.presigned_url_counter = None
         self.login_counter = None
         self.fence_login_counter = None
@@ -37,47 +36,47 @@ def initialize_metrics(self, app):
         self.presigned_url_counter = Counter(
             "fence_presigned_url_requests_total",
             "Total number of presigned URL requests",
-            registry=self.app.prometheus_registry,
+            registry=app.prometheus_registry,
         )
         self.login_counter = Counter(
             "fence_all_login_requests_total",
             "Total number of login requests",
-            registry=self.app.prometheus_registry,
+            registry=app.prometheus_registry,
         )
         self.fence_login_counter = Counter(
             "fence_login_requests_total",
             "Total number of fence login requests",
-            registry=self.app.prometheus_registry,
+            registry=app.prometheus_registry,
         )
         self.google_login_counter = Counter(
             "google_login_requests_total",
             "Total number of Google login requests",
-            registry=self.app.prometheus_registry,
+            registry=app.prometheus_registry,
         )
         self.ras_login_counter = Counter(
             "fence_ras_login_requests_total",
             "Total number of RAS login requests",
-            registry=self.app.prometheus_registry,
+            registry=app.prometheus_registry,
         )
         self.presigned_urls_ga4gh_drs_counter = Counter(
             "fence_presigned_urls_ga4gh_drs_requests_total",
             "Total number of presigned URL requests for GA4GH DRS",
-            registry=self.app.prometheus_registry,
+            registry=app.prometheus_registry,
         )
         self.presigned_url_download_protocol_gcs_counter = Counter(
             "fence_presigned_url_download_protocol_gcs_requests_total",
             "Total number of presigned URL requests for GCS",
-            registry=self.app.prometheus_registry,
+            registry=app.prometheus_registry,
         )
         self.presigned_url_download_protocol_s3_counter = Counter(
             "fence_presigned_url_download_protocol_s3_requests_total",
             "Total number of presigned URL requests for S3",
-            registry=self.app.prometheus_registry,
+            registry=app.prometheus_registry,
         )
         self.presigned_url_data_metrics_size_gauge = Gauge(
             "fence_presigned_url_data_metrics_size_bytes",
             "Size of data metrics in bytes",
-            registry=self.app.prometheus_registry,
+            registry=app.prometheus_registry,
         )