diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index faf961e..3cc2b91 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -15,7 +15,7 @@ jobs:
         os:
           - ubuntu-latest
         ocaml-compiler:
-          - 4.08.x
+          - 4.11.x
           - 4.14.x
           - 5.4.x
 
diff --git a/bin/opatch.ml b/bin/opatch.ml
index 83bc749..b6d584d 100644
--- a/bin/opatch.ml
+++ b/bin/opatch.ml
@@ -195,6 +195,7 @@ let main version =
         if verbose then
           Printf.printf "%S applied.\n%!" (Option.value ~default:"-" patch))
       patches
-  with Invalid_argument msg -> Printf.eprintf "Fatal error: %s\n" msg
+  with Invalid_argument msg ->
+    Printf.eprintf "Fatal error: %s\n" msg ; exit 1
 
 let () = main Version.v