diff --git a/tests/test-dirs/type-enclosing/503-effects.t b/tests/test-dirs/type-enclosing/503-effects.t
new file mode 100644
index 000000000..9982e6bef
--- /dev/null
+++ b/tests/test-dirs/type-enclosing/503-effects.t
@@ -0,0 +1,50 @@
+  $ cat >main.ml <<'EOF'
+  > open Effect
+  > open Effect.Deep
+  > 
+  > type _ eff += E : unit eff
+  > 
+  > let () =
+  >   Printf.printf "%d\n%!" @@
+  >     match 10 with
+  >     | x -> x
+  >     | effect E, k -> 11
+  > EOF
+
+  $ $MERLIN single errors -filename main.ml <main.ml
+  {
+    "class": "return",
+    "value": [],
+    "notifications": []
+  }
+
+  $ $MERLIN single type-enclosing -position 10:13 \
+  > -filename main.ml <main.ml | jq '.value[0]'
+  {
+    "start": {
+      "line": 10,
+      "col": 13
+    },
+    "end": {
+      "line": 10,
+      "col": 14
+    },
+    "type": "unit eff",
+    "tail": "no"
+  }
+
+FIXME: the continuation is invisible to Merlin
+  $ $MERLIN single type-enclosing -position 10:16 \
+  > -filename main.ml <main.ml | jq '.value[0]'
+  {
+    "start": {
+      "line": 8,
+      "col": 4
+    },
+    "end": {
+      "line": 10,
+      "col": 23
+    },
+    "type": "int",
+    "tail": "no"
+  }