diff --git a/containers.opam b/containers.opam
index 50acf25a..de68c511 100644
--- a/containers.opam
+++ b/containers.opam
@@ -12,7 +12,6 @@ bug-reports: "https://github.com/c-cube/ocaml-containers/issues"
 depends: [
   "dune" {>= "2.9"}
   "ocaml" {>= "4.08"}
-  "either"
   "dune-configurator"
   "qcheck-core" {>= "0.18" & with-test}
   "yojson" {with-test}
diff --git a/dune-project b/dune-project
index d05d4b37..8ff0e000 100644
--- a/dune-project
+++ b/dune-project
@@ -15,7 +15,6 @@
   (tags (stdlib containers iterators list heap queue))
   (depends
     (ocaml (>= 4.08))
-    either
     dune-configurator
     (qcheck-core (and (>= 0.18) :with-test))
     (yojson :with-test)
diff --git a/src/core/dune b/src/core/dune
index cc17ce83..38cd1d5b 100644
--- a/src/core/dune
+++ b/src/core/dune
@@ -6,7 +6,7 @@
   (action
    (run %{project_root}/src/core/cpp/cpp.exe %{input-file})))
  (flags :standard -nolabels -open CCMonomorphic)
- (libraries either containers.monomorphic))
+ (libraries containers.monomorphic))
 
 (ocamllex
  (modules CCSexp_lex))