diff --git a/dune-project b/dune-project
index a21f7d7c..023c0f58 100644
--- a/dune-project
+++ b/dune-project
@@ -56,8 +56,8 @@
   zarith
   (smtlib-utils
    (and
-    (>= "0.1")
-    (< "0.5")))
+    (>= "0.5")
+    (< "0.6")))
   (sidekick
    (= :version))
   (qcheck
diff --git a/sidekick-base.opam b/sidekick-base.opam
index f7611324..dcd97fce 100644
--- a/sidekick-base.opam
+++ b/sidekick-base.opam
@@ -10,7 +10,7 @@ bug-reports: "https://github.com/c-cube/sidekick/issues/"
 depends: [
   "dune" {>= "2.0"}
   "zarith"
-  "smtlib-utils" {>= "0.1" & < "0.5"}
+  "smtlib-utils" {>= "0.5" & < "0.6"}
   "sidekick" {= version}
   "qcheck" {with-test & >= "0.16"}
   "mdx" {with-test}