diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 000000000..ca79ca5b4
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,6 @@
+version: 2
+updates:
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly
diff --git a/.github/workflows/workflow.yml b/.github/workflows/workflow.yml
index 76030c564..b93c36085 100644
--- a/.github/workflows/workflow.yml
+++ b/.github/workflows/workflow.yml
@@ -1,8 +1,8 @@
 name: Main workflow
 
 on:
-  pull_request:
   push:
+  pull_request:
   schedule:
     # Prime the caches every Monday
     - cron: 0 1 * * MON
@@ -15,31 +15,30 @@ jobs:
         os:
           - ubuntu-latest
         ocaml-compiler:
-          - 4.04.x
-          - 4.05.x
-          - 4.11.x
-          - 4.13.x
-          - 4.14.x
-          - 5.0.x
-          - 5.1.x
+          - "4.04"
+          - "4.05"
+          - "4.11"
+          - "4.13"
+          - "4.14"
+          - "5.0"
+          - "5.1"
         include:
           - os: macos-latest
-            ocaml-compiler: 4.14.x
+            ocaml-compiler: "4.14"
           - os: windows-latest
-            ocaml-compiler: 4.14.x
-          - os: macos-latest
-            ocaml-compiler: 5.1.x
+            ocaml-compiler: "4.14"
 
     runs-on: ${{ matrix.os }}
 
     steps:
-      - name: Checkout code
-        uses: actions/checkout@v3
+      - name: Checkout tree
+        uses: actions/checkout@v4
 
-      - name: Use OCaml ${{ matrix.ocaml-compiler }}
+      - name: Set-up OCaml
         uses: ocaml/setup-ocaml@v2
         with:
           ocaml-compiler: ${{ matrix.ocaml-compiler }}
+          allow-prerelease-opam: true
           opam-depext-flags: --with-test
 
       - run: opam install . --deps-only --with-test
@@ -47,3 +46,17 @@ jobs:
       - run: opam exec -- make build
 
       - run: opam exec -- make test
+
+  lint-opam:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout tree
+        uses: actions/checkout@v4
+
+      - name: Set-up OCaml
+        uses: ocaml/setup-ocaml@v2
+        with:
+          ocaml-compiler: "4.14"
+          allow-prerelease-opam: true
+
+      - uses: ocaml/setup-ocaml/lint-opam@v2
diff --git a/dune-project b/dune-project
index 0decfd1b8..cc0ccfc3e 100644
--- a/dune-project
+++ b/dune-project
@@ -18,8 +18,8 @@
 "\| open Tyxml;
 "\| let to_reason = <a href=\"reasonml.github.io/\"> \"Reason!\" </a>
 "\| ```
-"\|  
-"\| The TyXML JSX allow to write TyXML documents with reason's JSX syntax. 
+"\|
+"\| The TyXML JSX allow to write TyXML documents with reason's JSX syntax.
 "\| It works with textual trees, virtual DOM trees, or any TyXML module.
 )
  (depends
@@ -35,13 +35,13 @@
 (package
  (name tyxml-ppx)
  (synopsis "PPX to write TyXML documents with the HTML syntax")
- (description 
+ (description
 "\| ```ocaml
 "\| open Tyxml
 "\| let%html to_ocaml = \"<a href='ocaml.org'>OCaml!</a>\"
 "\| ```
-"\|  
-"\| The TyXML PPX allow to write TyXML documents using the traditional HTML syntax. 
+"\|
+"\| The TyXML PPX allow to write TyXML documents using the traditional HTML syntax.
 "\| It works with textual trees, virtual DOM trees, or any TyXML module.
 )
  (depends
@@ -53,7 +53,9 @@
   (markup
    (>= 0.7.2))
   (ppxlib
-   (>= 0.18))))
+   (>= 0.18))
+  (re
+   (>= 1.5.0))))
 
 (package
  (name tyxml-syntax)
diff --git a/tyxml-jsx.opam b/tyxml-jsx.opam
index 05babce7d..f634341d0 100644
--- a/tyxml-jsx.opam
+++ b/tyxml-jsx.opam
@@ -6,8 +6,8 @@ description: """
 open Tyxml;
 let to_reason = <a href="reasonml.github.io/"> "Reason!" </a>
 ```
- 
-The TyXML JSX allow to write TyXML documents with reason's JSX syntax. 
+
+The TyXML JSX allow to write TyXML documents with reason's JSX syntax.
 It works with textual trees, virtual DOM trees, or any TyXML module.
 """
 maintainer: ["dev@ocsigen.org"]
diff --git a/tyxml-ppx.opam b/tyxml-ppx.opam
index 3b97f528a..1ef8e2ec0 100644
--- a/tyxml-ppx.opam
+++ b/tyxml-ppx.opam
@@ -6,8 +6,8 @@ description: """
 open Tyxml
 let%html to_ocaml = "<a href='ocaml.org'>OCaml!</a>"
 ```
- 
-The TyXML PPX allow to write TyXML documents using the traditional HTML syntax. 
+
+The TyXML PPX allow to write TyXML documents using the traditional HTML syntax.
 It works with textual trees, virtual DOM trees, or any TyXML module.
 """
 maintainer: ["dev@ocsigen.org"]
@@ -24,6 +24,7 @@ depends: [
   "alcotest" {with-test}
   "markup" {>= "0.7.2"}
   "ppxlib" {>= "0.18"}
+  "re" {>= "1.5.0"}
   "odoc" {with-doc}
 ]
 build: [
diff --git a/tyxml-syntax.opam b/tyxml-syntax.opam
index 5c04ead8b..2a5064fc4 100644
--- a/tyxml-syntax.opam
+++ b/tyxml-syntax.opam
@@ -9,7 +9,7 @@ doc: "https://ocsigen.org/tyxml/latest/manual/intro"
 bug-reports: "https://github.com/ocsigen/tyxml/issues"
 depends: [
   "dune" {>= "2.7"}
-  "ocaml" {>= "4.04"}
+  "ocaml" {>= "4.03"}
   "alcotest" {with-test}
   "ppxlib" {>= "0.18"}
   "re" {>= "1.5.0"}
diff --git a/tyxml.opam b/tyxml.opam
index d6384fd8f..3f9b2e251 100644
--- a/tyxml.opam
+++ b/tyxml.opam
@@ -11,7 +11,7 @@ doc: "https://ocsigen.org/tyxml/latest/manual/intro"
 bug-reports: "https://github.com/ocsigen/tyxml/issues"
 depends: [
   "dune" {>= "2.7"}
-  "ocaml" {>= "4.04"}
+  "ocaml" {>= "4.03"}
   "alcotest" {with-test}
   "re" {>= "1.5.0"}
   "seq"