diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 37f24faf..5863e343 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -18,7 +18,7 @@ jobs:
         ocaml-compiler:
             - '4.08'
             - '4.14'
-            - '5.1'
+            - '5.2'
 
     runs-on: ${{ matrix.os }}
     steps:
@@ -31,14 +31,14 @@ jobs:
           allow-prerelease-opam: true
 
       - run: opam install -t moonpool moonpool-lwt --deps-only
-        if: matrix.ocaml-compiler == '5.1'
+        if: matrix.ocaml-compiler == '5.2'
       - run: opam install -t moonpool --deps-only
-        if: matrix.ocaml-compiler != '5.1'
+        if: matrix.ocaml-compiler != '5.2'
       - run: opam exec -- dune build @install
 
       # install some depopts
       - run: opam install thread-local-storage trace domain-local-await
-        if: matrix.ocaml-compiler == '5.1'
+        if: matrix.ocaml-compiler == '5.2'
 
       - run: opam exec -- dune build --profile=release --force @install @runtest
 
@@ -52,7 +52,7 @@ jobs:
             - macos-latest
               #- windows-latest
         ocaml-compiler:
-            - '5.1'
+            - '5.2'
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@main
@@ -74,7 +74,7 @@ jobs:
     strategy:
       matrix:
         ocaml-compiler:
-            - '5.1'
+            - '5.2'
     runs-on: 'ubuntu-latest'
     steps:
       - uses: actions/checkout@main
@@ -85,6 +85,6 @@ jobs:
           dune-cache: true
           allow-prerelease-opam: true
 
-      - run: opam install ocamlformat.0.24.1
+      - run: opam install ocamlformat.0.26.2
       - run: opam exec -- make format-check
 
diff --git a/.ocamlformat b/.ocamlformat
index 2124d7dd..78183459 100644
--- a/.ocamlformat
+++ b/.ocamlformat
@@ -1,4 +1,4 @@
-version = 0.24.1
+version = 0.26.2
 profile=conventional
 margin=80
 if-then-else=k-r
diff --git a/benchs/pi.ml b/benchs/pi.ml
index 63ddc2ca..e9d333f5 100644
--- a/benchs/pi.ml
+++ b/benchs/pi.ml
@@ -149,7 +149,7 @@ let () =
   Printf.printf "pi=%.6f (pi=%.6f, diff=%.3f)%s\n%!" res Float.pi
     (abs_float (Float.pi -. res))
     (if !time then
-      spf " in %.4fs" elapsed
-    else
-      "");
+       spf " in %.4fs" elapsed
+     else
+       "");
   ()
diff --git a/src/lwt/IO_in.ml b/src/lwt/IO_in.ml
index a0e2744a..0a7e33bc 100644
--- a/src/lwt/IO_in.ml
+++ b/src/lwt/IO_in.ml
@@ -1,14 +1,13 @@
 open Common_
 
-class type t =
-  object
-    method input : bytes -> int -> int -> int
-    (** Read into the slice. Returns [0] only if the
+class type t = object
+  method input : bytes -> int -> int -> int
+  (** Read into the slice. Returns [0] only if the
         stream is closed. *)
 
-    method close : unit -> unit
-    (** Close the input. Must be idempotent. *)
-  end
+  method close : unit -> unit
+  (** Close the input. Must be idempotent. *)
+end
 
 let create ?(close = ignore) ~input () : t =
   object
diff --git a/src/lwt/IO_out.ml b/src/lwt/IO_out.ml
index 9c1207dc..522d3e0a 100644
--- a/src/lwt/IO_out.ml
+++ b/src/lwt/IO_out.ml
@@ -1,12 +1,11 @@
 open Common_
 
-class type t =
-  object
-    method output_char : char -> unit
-    method output : bytes -> int -> int -> unit
-    method flush : unit -> unit
-    method close : unit -> unit
-  end
+class type t = object
+  method output_char : char -> unit
+  method output : bytes -> int -> int -> unit
+  method flush : unit -> unit
+  method close : unit -> unit
+end
 
 let create ?(flush = ignore) ?(close = ignore) ~output_char ~output () : t =
   object