diff --git a/src/client-cohttp-lwt/opentelemetry_client_cohttp_lwt.ml b/src/client-cohttp-lwt/opentelemetry_client_cohttp_lwt.ml
index 8e617852..e1625bd2 100644
--- a/src/client-cohttp-lwt/opentelemetry_client_cohttp_lwt.ml
+++ b/src/client-cohttp-lwt/opentelemetry_client_cohttp_lwt.ml
@@ -559,6 +559,9 @@ end
 
 let setup_ ?(stop = Atomic.make false) ~(config : Config.t) () =
   debug_ := config.debug;
+
+  if config.url <> get_url () then set_url config.url;
+
   let module B =
     Backend
       (struct
diff --git a/src/client-ocurl/opentelemetry_client_ocurl.ml b/src/client-ocurl/opentelemetry_client_ocurl.ml
index 2ad599f1..812b4f6b 100644
--- a/src/client-ocurl/opentelemetry_client_ocurl.ml
+++ b/src/client-ocurl/opentelemetry_client_ocurl.ml
@@ -446,6 +446,8 @@ let setup_ ?(stop = Atomic.make false) ~(config : Config.t) () =
   let ((module B) as backend) = mk_backend ~stop ~config () in
   Opentelemetry.Collector.set_backend backend;
 
+  if config.url <> get_url () then set_url config.url;
+
   if config.ticker_thread then (
     let sleep_ms = min 5_000 (max 2 config.batch_timeout_ms) in
     ignore (setup_ticker_thread ~stop ~sleep_ms backend () : Thread.t)
diff --git a/tests/test_get_url.expected b/tests/test_get_url.expected
index 37c0d86a..bafd6ea4 100644
--- a/tests/test_get_url.expected
+++ b/tests/test_get_url.expected
@@ -1,2 +1,2 @@
-ocurl url = http://localhost:4318
-cohttp url = http://localhost:4318
+ocurl url = http://localhost:3000
+cohttp url = http://localhost:3000