diff --git a/dune-project b/dune-project
index 57a857f4..952bcc36 100644
--- a/dune-project
+++ b/dune-project
@@ -140,7 +140,7 @@
   (odoc :with-doc)
   (cohttp-eio
    (>= 6.1.0))
-  eio_main
+  (eio_main :with-test)
   tls-eio
   (alcotest :with-test)
   (containers :with-test))
diff --git a/opentelemetry-client-cohttp-eio.opam b/opentelemetry-client-cohttp-eio.opam
index fc59603a..4a4eb785 100644
--- a/opentelemetry-client-cohttp-eio.opam
+++ b/opentelemetry-client-cohttp-eio.opam
@@ -20,7 +20,7 @@ depends: [
   "opentelemetry" {= version}
   "odoc" {with-doc}
   "cohttp-eio" {>= "6.1.0"}
-  "eio_main"
+  "eio_main" {with-test}
   "tls-eio"
   "alcotest" {with-test}
   "containers" {with-test}