diff --git a/puppet/zulip/files/postgresql/env-wal-g b/puppet/zulip/files/postgresql/env-wal-g
index a397e8d637..e68c7604c3 100755
--- a/puppet/zulip/files/postgresql/env-wal-g
+++ b/puppet/zulip/files/postgresql/env-wal-g
@@ -10,7 +10,7 @@ export WALG_DELTA_MAX_STEPS
 
 s3_backups_bucket=$(crudini --get "$ZULIP_SECRETS_CONF" secrets s3_backups_bucket 2>/dev/null)
 
-if [ "$s3_backups_bucket" != "" ]; then
+if [ "$s3_backups_bucket" != "" ] || [ -n "$WALG_S3_PREFIX" ]; then
     AWS_REGION=$(crudini --get "$ZULIP_SECRETS_CONF" secrets s3_region 2>/dev/null)
     if [ "$AWS_REGION" = "" ]; then
         # Fall back to the current region, if possible
@@ -24,7 +24,8 @@ if [ "$s3_backups_bucket" != "" ]; then
     export AWS_ACCESS_KEY_ID
     AWS_SECRET_ACCESS_KEY=$(crudini --get "$ZULIP_SECRETS_CONF" secrets s3_backups_secret_key 2>/dev/null)
     export AWS_SECRET_ACCESS_KEY
-    export WALG_S3_PREFIX="s3://$s3_backups_bucket"
+    : "${WALG_S3_PREFIX:=s3://$s3_backups_bucket}"
+    export WALG_S3_PREFIX
 
     if storage_class=$(crudini --get /etc/zulip/zulip.conf postgresql backups_storage_class 2>&1); then
         export WALG_S3_STORAGE_CLASS="$storage_class"
diff --git a/puppet/zulip/files/postgresql/wal-g-exporter b/puppet/zulip/files/postgresql/wal-g-exporter
index edb2790717..b5fb1bef52 100755
--- a/puppet/zulip/files/postgresql/wal-g-exporter
+++ b/puppet/zulip/files/postgresql/wal-g-exporter
@@ -3,12 +3,14 @@ import configparser
 import contextlib
 import json
 import logging
+import os
 import subprocess
 import sys
 from collections import defaultdict
 from datetime import datetime, timedelta, timezone
 from http.server import BaseHTTPRequestHandler, HTTPServer
 from typing import Dict, List, Mapping, Optional, Protocol
+from urllib.parse import parse_qs, urlsplit
 
 
 class GaugeMetric(Protocol):
@@ -54,7 +56,7 @@ class WalGPrometheusServer(BaseHTTPRequestHandler):
         self.wfile.write("\n".join(lines).encode())
 
     def do_GET(self) -> None:
-        if self.path != "/metrics":
+        if urlsplit(self.path).path != "/metrics":
             self.send_response(404)
             self.end_headers()
             sys.stderr.flush()
@@ -89,13 +91,20 @@ class WalGPrometheusServer(BaseHTTPRequestHandler):
 
         now = datetime.now(tz=timezone.utc)
         try:
-            config_file = configparser.RawConfigParser()
-            config_file.read("/etc/zulip/zulip-secrets.conf")
-            bucket = config_file["secrets"]["s3_backups_bucket"]
+            query = parse_qs(urlsplit(self.path).query)
+            modified_env = os.environ.copy()
+            if query.get("bucket") and len(query["bucket"]) == 1:
+                bucket = query["bucket"][0]
+                modified_env["WALG_S3_PREFIX"] = f"s3://{bucket}"
+            else:
+                config_file = configparser.RawConfigParser()
+                config_file.read("/etc/zulip/zulip-secrets.conf")
+                bucket = config_file["secrets"]["s3_backups_bucket"]
 
             backup_list_output = subprocess.check_output(
                 ["env-wal-g", "backup-list", "--detail", "--json"],
                 text=True,
+                env=modified_env,
             )
             data = json.loads(backup_list_output)
             backup_count(len(data), {"bucket": bucket})