diff --git a/test/blackbox-tests/mel-as-in-external.t b/test/blackbox-tests/mel-as-in-external.t
new file mode 100644
index 0000000000..00f1afbcb3
--- /dev/null
+++ b/test/blackbox-tests/mel-as-in-external.t
@@ -0,0 +1,101 @@
+Test the attribute @mel.as in external with @mel.set
+
+  $ . ./setup.sh
+
+  $ cat > x.ml <<\EOF
+  > type document
+  > 
+  > external document : document = "document"
+  > 
+  > external transition :
+  >   document ->
+  >   [ `ease
+  >   | `easeIn [@mel.as "ease-in"]
+  >   | `easeOut [@mel.as "ease-out"]
+  >   | `easeInOut [@mel.as "ease-in-out"]
+  >   | `linear ] ->
+  >   unit = "transitionTimingFunction"
+  > [@@mel.set]
+  > 
+  > let () = transition document `easeIn
+  > EOF
+
+  $ cat > dune-project <<EOF
+  > (lang dune 3.8)
+  > (using melange 0.1)
+  > EOF
+
+  $ cat > dune <<EOF
+  > (melange.emit
+  >  (target out)
+  >  (emit_stdlib false)
+  >  (preprocess (pps melange.ppx)))
+  > EOF
+
+When `mel.string` is not used, the compiler complains
+
+  $ dune build @melange
+  File "x.ml", line 8, characters 14-20:
+  8 |   | `easeIn [@mel.as "ease-in"]
+                    ^^^^^^
+  Alert unused: Unused attribute [@mel.as]
+  This means such annotation is not annotated properly.
+  For example, some annotations are only meaningful in externals
+  
+  
+  File "x.ml", line 9, characters 15-21:
+  9 |   | `easeOut [@mel.as "ease-out"]
+                     ^^^^^^
+  Alert unused: Unused attribute [@mel.as]
+  This means such annotation is not annotated properly.
+  For example, some annotations are only meaningful in externals
+  
+  
+  File "x.ml", line 10, characters 17-23:
+  10 |   | `easeInOut [@mel.as "ease-in-out"]
+                        ^^^^^^
+  Alert unused: Unused attribute [@mel.as]
+  This means such annotation is not annotated properly.
+  For example, some annotations are only meaningful in externals
+  
+The `mel.as` attribute has no effect in the output
+
+  $ cat ./_build/default/out/x.js
+  // Generated by Melange
+  'use strict';
+  
+  
+  document.transitionTimingFunction = "easeIn";
+  
+  /*  Not a pure module */
+
+  $ cat > x.ml <<\EOF
+  > type document
+  > 
+  > external document : document = "document"
+  > 
+  > external transition :
+  >   document ->
+  >   ([ `ease
+  >   | `easeIn [@mel.as "ease-in"]
+  >   | `easeOut [@mel.as "ease-out"]
+  >   | `easeInOut [@mel.as "ease-in-out"]
+  >   | `linear ] [@mel.string]) ->
+  >   unit = "transitionTimingFunction"
+  > [@@mel.set]
+  > 
+  > let () = transition document `easeIn
+  > EOF
+
+Using @mel.string fixes it
+
+  $ dune build @melange
+
+  $ cat ./_build/default/out/x.js
+  // Generated by Melange
+  'use strict';
+  
+  
+  document.transitionTimingFunction = "ease-in";
+  
+  /*  Not a pure module */