diff --git a/src/core/opamUrl.ml b/src/core/opamUrl.ml
index f0374cca5ea..30333f43c4c 100644
--- a/src/core/opamUrl.ml
+++ b/src/core/opamUrl.ml
@@ -37,7 +37,7 @@ let split_url =
         opt @@ seq [
           (* Backend *)
           opt @@ seq [ group @@ rep @@ diff any (set "+:");
-                       alt [ char '+'; str "://"] ];
+                       char '+' ];
           (* Protocol *)
           group @@ rep @@ diff any (char ':');
           (* Separator *)