diff --git a/dune-project b/dune-project
index 0ef4777..918951b 100644
--- a/dune-project
+++ b/dune-project
@@ -68,7 +68,7 @@
   base-unix
   dune)
  (tags
-  (trace tracing catapult TEF chrome-format)))
+  (trace tracing catapult TEF chrome-format chrome-trace json)))
 
 (package
  (name trace-fuchsia)
diff --git a/trace-tef.opam b/trace-tef.opam
index e2c3926..52d2733 100644
--- a/trace-tef.opam
+++ b/trace-tef.opam
@@ -6,7 +6,9 @@ synopsis:
 maintainer: ["Simon Cruanes"]
 authors: ["Simon Cruanes"]
 license: "MIT"
-tags: ["trace" "tracing" "catapult" "TEF" "chrome-format"]
+tags: [
+  "trace" "tracing" "catapult" "TEF" "chrome-format" "chrome-trace" "json"
+]
 homepage: "https://github.com/c-cube/ocaml-trace"
 bug-reports: "https://github.com/c-cube/ocaml-trace/issues"
 depends: [