diff --git a/dune-project b/dune-project
index b6f6984..b3f149e 100644
--- a/dune-project
+++ b/dune-project
@@ -20,4 +20,4 @@
  (authors "Geoffrey Borough")
  (synopsis "A type safe money manipulation library")
  (description "A type safe money manipulation library")
- (depends (ocaml (>= 4.14.0)) base dune (zarith (>= 1.5.0)) stdint (angstrom (>= 0.7.0)) re2 yojson ppx_deriving ppx_deriving_yojson ppx_jane (ppx_expect :with-test)))
+ (depends (ocaml (>= 4.14.0)) base dune (zarith (>= 1.5.0)) stdint (angstrom (>= 0.16.0)) re2 yojson ppx_deriving ppx_deriving_yojson ppx_jane (ppx_expect :with-test)))
diff --git a/safemoney.opam b/safemoney.opam
index e2e0478..72c4db4 100644
--- a/safemoney.opam
+++ b/safemoney.opam
@@ -14,7 +14,7 @@ depends: [
   "dune" {>= "3.0"}
   "zarith" {>= "1.5.0"}
   "stdint"
-  "angstrom" {>= "0.7.0"}
+  "angstrom" {>= "0.16.0"}
   "re2"
   "yojson"
   "ppx_deriving"