diff --git a/README.md b/README.md
index e3fd95c..438750d 100644
--- a/README.md
+++ b/README.md
@@ -38,6 +38,8 @@ Available tags are:
 *   `js-only` for tests that should only run in Javascript
 *   `32-bits-only` for tests that should only run in 32 bits architectures
 *   `64-bits-only` for tests that should only run in 64 bits architectures
+*   `fast-flambda` for tests that might only pass when compiling with flambda, -O3
+    and cross library inlining
 *   `x-library-inlining-sensitive` for tests that might only pass when compiling
     with cross library inlining switched on
 
diff --git a/ppx_inline_test.opam b/ppx_inline_test.opam
index 492b376..e6e3446 100644
--- a/ppx_inline_test.opam
+++ b/ppx_inline_test.opam
@@ -12,7 +12,7 @@ build: [
 depends: [
   "ocaml" {>= "4.04.2"}
   "base"
-  "dune"   {>= "1.5.1"}
+  "dune"   {>= "2.0.0"}
   "ppxlib" {>= "0.9.0"}
 ]
 synopsis: "Syntax extension for writing in-line tests in ocaml code"
diff --git a/src/ppx_inline_test.ml b/src/ppx_inline_test.ml
index 4edabdb..8a477dd 100644
--- a/src/ppx_inline_test.ml
+++ b/src/ppx_inline_test.ml
@@ -115,7 +115,9 @@ let all_tags =
   ; "js-only"
   ; "64-bits-only"
   ; "32-bits-only"
-  ; "x-library-inlining-sensitive" ]
+  ; "fast-flambda"
+  ; "x-library-inlining-sensitive"
+  ]
 
 let validate_tag tag =
   if not (List.mem all_tags tag ~equal:String.equal)