diff --git a/src/lib_rules.ml b/src/lib_rules.ml
index 7deb093c..6f5abe3f 100644
--- a/src/lib_rules.ml
+++ b/src/lib_rules.ml
@@ -137,8 +137,8 @@ module Gen (P : Install_rules.Params) = struct
         let name = Module.Name.to_string name in
         let hidden_name = sprintf "%s__%s" lib_name name in
         let real_name = sprintf "%s.%s" lib_name name in
-        sprintf "include %s [@@deprecated \"%s. Use %s instead.\"]"
-          hidden_name transition_message real_name
+        sprintf {|[@@@deprecated "%s. Use %s instead."] include %s|}
+          transition_message real_name hidden_name
       in
       let source_path = Option.value_exn (Module.file m Impl) in
       Build.return contents
diff --git a/test/blackbox-tests/test-cases/wrapped-transition/run.t b/test/blackbox-tests/test-cases/wrapped-transition/run.t
index 2e9a5d3b..76b1fea0 100644
--- a/test/blackbox-tests/test-cases/wrapped-transition/run.t
+++ b/test/blackbox-tests/test-cases/wrapped-transition/run.t
@@ -1,6 +1,7 @@
-  $ dune build
-        fooexe alias default
-  bar
-  foo
-  bar
-  foo
+  $ dune build 2>&1 | grep -v ocamlc
+  File "fooexe.ml", line 3, characters 0-7:
+  Error (warning 3): deprecated: module Bar
+  Will be removed past 2020-20-20. Use Mylib.Bar instead.
+  File "fooexe.ml", line 4, characters 0-7:
+  Error (warning 3): deprecated: module Foo
+  Will be removed past 2020-20-20. Use Mylib.Foo instead.