diff --git a/swh/icinga_plugins/deposit.py b/swh/icinga_plugins/deposit.py
--- a/swh/icinga_plugins/deposit.py
+++ b/swh/icinga_plugins/deposit.py
@@ -175,9 +175,11 @@
 
         # Get metadata list from swh-web
         metadata_objects = requests.get(
-            f"{self.api_url}/api/1/raw-extrinsic-metadata/swhid/{swhid}/"
-            f"?authority=deposit_client%20{self._provider_url}"
-            f"&after={start_datetime.isoformat()}"
+            f"{self.api_url}/api/1/raw-extrinsic-metadata/swhid/{swhid}/",
+            params={
+                "authority": f"deposit_client {self._provider_url}",
+                "after": start_datetime.isoformat(),
+            },
         ).json()
         expected_origin = f"{self._provider_url}/{self._slug}"
 
diff --git a/swh/icinga_plugins/tests/test_deposit.py b/swh/icinga_plugins/tests/test_deposit.py
--- a/swh/icinga_plugins/tests/test_deposit.py
+++ b/swh/icinga_plugins/tests/test_deposit.py
@@ -19,7 +19,7 @@
 POLL_INTERVAL = 10
 
 BASE_URL = "http://swh-deposit.example.org/1"
-BASE_WEB_URL = "mock://swh-web.example.org"
+BASE_WEB_URL = "http+mock://swh-web.example.org"
 PROVIDER_URL = "http://icinga-checker.example.org"
 
 COMMON_OPTIONS = [
@@ -213,8 +213,8 @@
     scenario.add_step(
         "get",
         f"{BASE_WEB_URL}/api/1/raw-extrinsic-metadata/swhid/{swhid}/"
-        f"?authority=deposit_client%20http://icinga-checker.example.org"
-        f"&after=2022-03-04T17:02:39+00:00",
+        f"?authority=deposit_client+http%3A%2F%2Ficinga-checker.example.org"
+        f"&after=2022-03-04T17%3A02%3A39%2B00%3A00",
         [
             {
                 "swhid": swhid,
@@ -296,8 +296,8 @@
     scenario.add_step(
         "get",
         f"{BASE_WEB_URL}/api/1/raw-extrinsic-metadata/swhid/{swhid}/"
-        f"?authority=deposit_client%20http://icinga-checker.example.org"
-        f"&after=2022-03-04T17:02:39+00:00",
+        f"?authority=deposit_client+http%3A%2F%2Ficinga-checker.example.org"
+        f"&after=2022-03-04T17%3A02%3A39%2B00%3A00",
         [
             {
                 "swhid": swhid,
@@ -377,8 +377,8 @@
     scenario.add_step(
         "get",
         f"{BASE_WEB_URL}/api/1/raw-extrinsic-metadata/swhid/{swhid}/"
-        f"?authority=deposit_client%20http://icinga-checker.example.org"
-        f"&after=2022-03-04T17:02:39+00:00",
+        f"?authority=deposit_client+http%3A%2F%2Ficinga-checker.example.org"
+        f"&after=2022-03-04T17%3A02%3A39%2B00%3A00",
         [
             {
                 "swhid": swhid,
@@ -453,8 +453,8 @@
     scenario.add_step(
         "get",
         f"{BASE_WEB_URL}/api/1/raw-extrinsic-metadata/swhid/{swhid}/"
-        f"?authority=deposit_client%20http://icinga-checker.example.org"
-        f"&after=2022-03-04T17:02:39+00:00",
+        f"?authority=deposit_client+http%3A%2F%2Ficinga-checker.example.org"
+        f"&after=2022-03-04T17%3A02%3A39%2B00%3A00",
         [
             {
                 "swhid": swhid,
@@ -520,8 +520,8 @@
     scenario.add_step(
         "get",
         f"{BASE_WEB_URL}/api/1/raw-extrinsic-metadata/swhid/{swhid}/"
-        f"?authority=deposit_client%20http://icinga-checker.example.org"
-        f"&after=2022-03-04T17:02:39+00:00",
+        f"?authority=deposit_client+http%3A%2F%2Ficinga-checker.example.org"
+        f"&after=2022-03-04T17%3A02%3A39%2B00%3A00",
         [
             {
                 "swhid": swhid,
@@ -642,8 +642,8 @@
     scenario.add_step(
         "get",
         f"{BASE_WEB_URL}/api/1/raw-extrinsic-metadata/swhid/{swhid}/"
-        f"?authority=deposit_client%20http://icinga-checker.example.org"
-        f"&after=2022-03-04T17:02:39+00:00",
+        f"?authority=deposit_client+http%3A%2F%2Ficinga-checker.example.org"
+        f"&after=2022-03-04T17%3A02%3A39%2B00%3A00",
         metadata_list,
     )
 
@@ -705,8 +705,8 @@
     scenario.add_step(
         "get",
         f"{BASE_WEB_URL}/api/1/raw-extrinsic-metadata/swhid/{swhid}/"
-        f"?authority=deposit_client%20http://icinga-checker.example.org"
-        f"&after=2022-03-04T17:02:39+00:00",
+        f"?authority=deposit_client+http%3A%2F%2Ficinga-checker.example.org"
+        f"&after=2022-03-04T17%3A02%3A39%2B00%3A00",
         metadata_list,
     )
     scenario.add_step(