diff --git a/packages/tar/tar.0.9.0/opam b/packages/tar/tar.0.9.0/opam
index b1159a620154..efbf96475d16 100644
--- a/packages/tar/tar.0.9.0/opam
+++ b/packages/tar/tar.0.9.0/opam
@@ -13,7 +13,7 @@ build: [
 ]
 
 depends: [
-  "ocaml" {>= "4.03.0"}
+  "ocaml" {>= "4.03.0" & < "5.0"}
   "jbuilder" {>= "1.0+beta7"}
   "ppx_tools"
   "ppx_cstruct" {<"3.4.0"}
diff --git a/packages/tar/tar.1.0.0/opam b/packages/tar/tar.1.0.0/opam
index 9c588519fea0..dba0eb88e00b 100644
--- a/packages/tar/tar.1.0.0/opam
+++ b/packages/tar/tar.1.0.0/opam
@@ -6,7 +6,7 @@ homepage: "https://github.com/mirage/ocaml-tar"
 doc: "https://mirage.github.io/ocaml-tar/"
 bug-reports: "https://github.com/mirage/ocaml-tar/issues"
 depends: [
-  "ocaml" {>= "4.03.0"}
+  "ocaml" {>= "4.03.0" & < "5.0"}
   "dune" {>= "1.0"}
   "ppx_tools" {build}
   "ppx_cstruct" {>= "3.1.0"}
diff --git a/packages/tar/tar.1.0.1/opam b/packages/tar/tar.1.0.1/opam
index 29fbc163b9c3..0f5811ff0353 100644
--- a/packages/tar/tar.1.0.1/opam
+++ b/packages/tar/tar.1.0.1/opam
@@ -6,7 +6,7 @@ homepage: "https://github.com/mirage/ocaml-tar"
 doc: "https://mirage.github.io/ocaml-tar/"
 bug-reports: "https://github.com/mirage/ocaml-tar/issues"
 depends: [
-  "ocaml" {>= "4.03.0"}
+  "ocaml" {>= "4.03.0" & < "5.0"}
   "dune" {>= "1.0"}
   "ppx_tools" {build}
   "ppx_cstruct" {>= "3.1.0"}
diff --git a/packages/tar/tar.1.1.0/opam b/packages/tar/tar.1.1.0/opam
index de9dc4320127..66f7c585d96f 100644
--- a/packages/tar/tar.1.1.0/opam
+++ b/packages/tar/tar.1.1.0/opam
@@ -6,7 +6,7 @@ homepage: "https://github.com/mirage/ocaml-tar"
 doc: "https://mirage.github.io/ocaml-tar/"
 bug-reports: "https://github.com/mirage/ocaml-tar/issues"
 depends: [
-  "ocaml" {>= "4.03.0"}
+  "ocaml" {>= "4.03.0" & < "5.0"}
   "dune" {>= "1.0"}
   "ppx_tools" {build}
   "ppx_cstruct" {>= "3.6.0"}
diff --git a/packages/tar/tar.2.0.0/opam b/packages/tar/tar.2.0.0/opam
index ec44285d48a4..bfd6dc354a44 100644
--- a/packages/tar/tar.2.0.0/opam
+++ b/packages/tar/tar.2.0.0/opam
@@ -15,7 +15,7 @@ doc: "https://mirage.github.io/ocaml-tar/"
 bug-reports: "https://github.com/mirage/ocaml-tar/issues"
 depends: [
   "dune" {>= "2.9"}
-  "ocaml" {>= "4.08.0"}
+  "ocaml" {>= "4.08.0" & < "5.0"}
   "ppx_cstruct" {build & >= "3.6.0"}
   "cstruct" {>= "6.0.0"}
   "re" {>= "1.7.2"}