diff --git a/ocaml/testsuite/tests/typing-layouts-float64/alloc.ml b/ocaml/testsuite/tests/typing-layouts-float64/alloc.ml
index eba22c61adb..816db8b5ddb 100644
--- a/ocaml/testsuite/tests/typing-layouts-float64/alloc.ml
+++ b/ocaml/testsuite/tests/typing-layouts-float64/alloc.ml
@@ -6,30 +6,15 @@
 (* A test comparing allocations with unboxed floats to allocations with boxed
    floats. *)
 
-(* CR layouts v2: Delete this `Float_u` module and use the one we add to the
-   standard library instead. *)
-module type Float_u = sig
-  external to_float : float# -> (float[@local_opt]) = "%box_float"
-  external of_float : (float[@local_opt]) -> float# = "%unbox_float"
-
-  val ( + ) : float# -> float# -> float#
-  val ( - ) : float# -> float# -> float#
-  val ( * ) : float# -> float# -> float#
-  val ( / ) : float# -> float# -> float#
-  val ( ** ) : float# -> float# -> float#
-  val ( > ) : float# -> float# -> bool
-end
-
-module Float_u : Float_u = struct
-  external to_float : float# -> (float[@local_opt]) = "%box_float"
-  external of_float : (float[@local_opt]) -> float# = "%unbox_float"
-
-  let ( + ) x y = of_float ((to_float x) +. (to_float y))
-  let ( - ) x y = of_float ((to_float x) -. (to_float y))
-  let ( * ) x y = of_float ((to_float x) *. (to_float y))
-  let ( / ) x y = of_float ((to_float x) /. (to_float y))
-  let ( ** ) x y = of_float ((to_float x) ** (to_float y))
-  let ( > ) x y = (to_float x) > (to_float y)
+module Float_u = struct
+  include Stdlib__Float_u
+
+  let ( + ) = add
+  let ( - ) = sub
+  let ( * ) = mul
+  let ( / ) = div
+  let ( ** ) = pow
+  let ( > ) x y = (compare x y) > 0
 end
 
 let alloc = ref 0.0
diff --git a/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats.compilers.reference b/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats.compilers.reference
index bdd5cc8d3fe..c89d2a2a147 100644
--- a/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats.compilers.reference
+++ b/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats.compilers.reference
@@ -1,4 +1,4 @@
-File "unboxed_floats.ml", line 21, characters 22-28:
-21 |   external to_float : float# -> (float[@local_opt]) = "%box_float"
-                           ^^^^^^
-Error: This construct requires the alpha version of the extension "layouts", which is disabled and cannot be used
+File "unboxed_floats.ml", line 74, characters 11-18:
+74 | type ('a : float64) t_float64 = 'a
+                ^^^^^^^
+Error: Layout float64 is used here, but the appropriate layouts extension is not enabled
diff --git a/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats.ml b/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats.ml
index fde0cc869ca..e715f44f62b 100644
--- a/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats.ml
+++ b/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats.ml
@@ -17,35 +17,17 @@
 (*****************************************)
 (* Prelude: Functions on unboxed floats. *)
 
-module type Float_u = sig
-  external to_float : float# -> (float[@local_opt]) = "%box_float"
-  external of_float : (float[@local_opt]) -> float# = "%unbox_float"
-
-  val ( + ) : float# -> float# -> float#
-  val ( - ) : float# -> float# -> float#
-  val ( * ) : float# -> float# -> float#
-  val ( / ) : float# -> float# -> float#
-  val ( ** ) : float# -> float# -> float#
-  val ( > ) : float# -> float# -> bool
+module Float_u = struct
+  include Stdlib__Float_u
+
+  let ( + ) = add
+  let ( - ) = sub
+  let ( * ) = mul
+  let ( / ) = div
+  let ( ** ) = pow
+  let ( > ) x y = (compare x y) > 0
 end
 
-module Float_u : Float_u = struct
-  external to_float : float# -> (float[@local_opt]) = "%box_float"
-  external of_float : (float[@local_opt]) -> float# = "%unbox_float"
-
-  (* We may in the future add primitives for these, but for now this has proven
-     to be good enough - the boxing/unboxing is eliminated on all
-     middle-ends. *)
-  let[@inline always] ( + ) x y = of_float ((to_float x) +. (to_float y))
-  let[@inline always] ( - ) x y = of_float ((to_float x) -. (to_float y))
-  let[@inline always] ( * ) x y = of_float ((to_float x) *. (to_float y))
-  let[@inline always] ( / ) x y = of_float ((to_float x) /. (to_float y))
-  let[@inline always] ( ** ) x y = of_float ((to_float x) ** (to_float y))
-  let[@inline always] ( > ) x y = (to_float x) > (to_float y)
-end
-
-(* CR layouts v2: move this into a stand-alone [Float_u] module *)
-
 (*********************************)
 (* Test 1: some basic arithmetic *)
 
diff --git a/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats_alpha.ml b/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats_alpha.ml
index 6f1a5a6d1f9..bde12e86733 100644
--- a/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats_alpha.ml
+++ b/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats_alpha.ml
@@ -11,35 +11,17 @@
 (*****************************************)
 (* Prelude: Functions on unboxed floats. *)
 
-module type Float_u = sig
-  external to_float : float# -> (float[@local_opt]) = "%box_float"
-  external of_float : (float[@local_opt]) -> float# = "%unbox_float"
-
-  val ( + ) : float# -> float# -> float#
-  val ( - ) : float# -> float# -> float#
-  val ( * ) : float# -> float# -> float#
-  val ( / ) : float# -> float# -> float#
-  val ( ** ) : float# -> float# -> float#
-  val ( > ) : float# -> float# -> bool
+module Float_u = struct
+  include Stdlib__Float_u
+
+  let ( + ) = add
+  let ( - ) = sub
+  let ( * ) = mul
+  let ( / ) = div
+  let ( ** ) = pow
+  let ( > ) x y = (compare x y) > 0
 end
 
-module Float_u : Float_u = struct
-  external to_float : float# -> (float[@local_opt]) = "%box_float"
-  external of_float : (float[@local_opt]) -> float# = "%unbox_float"
-
-  (* We may in the future add primitives for these, but for now this has proven
-     to be good enough - the boxing/unboxing is eliminated on all
-     middle-ends. *)
-  let[@inline always] ( + ) x y = of_float ((to_float x) +. (to_float y))
-  let[@inline always] ( - ) x y = of_float ((to_float x) -. (to_float y))
-  let[@inline always] ( * ) x y = of_float ((to_float x) *. (to_float y))
-  let[@inline always] ( / ) x y = of_float ((to_float x) /. (to_float y))
-  let[@inline always] ( ** ) x y = of_float ((to_float x) ** (to_float y))
-  let[@inline always] ( > ) x y = (to_float x) > (to_float y)
-end
-
-(* CR layouts v2: move this into a stand-alone [Float_u] module *)
-
 (*********************************)
 (* Test 1: some basic arithmetic *)
 
diff --git a/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats_beta.compilers.reference b/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats_beta.compilers.reference
index 6c4a93e135e..003bda1cb3b 100644
--- a/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats_beta.compilers.reference
+++ b/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats_beta.compilers.reference
@@ -1,4 +1,4 @@
-File "unboxed_floats_beta.ml", line 21, characters 22-28:
-21 |   external to_float : float# -> (float[@local_opt]) = "%box_float"
-                           ^^^^^^
-Error: This construct requires the alpha version of the extension "layouts", which is disabled and cannot be used
+File "unboxed_floats_beta.ml", line 74, characters 11-18:
+74 | type ('a : float64) t_float64 = 'a
+                ^^^^^^^
+Error: Layout float64 is used here, but the appropriate layouts extension is not enabled
diff --git a/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats_beta.ml b/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats_beta.ml
index 0032d72389f..490523454a7 100644
--- a/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats_beta.ml
+++ b/ocaml/testsuite/tests/typing-layouts-float64/unboxed_floats_beta.ml
@@ -17,35 +17,17 @@
 (*****************************************)
 (* Prelude: Functions on unboxed floats. *)
 
-module type Float_u = sig
-  external to_float : float# -> (float[@local_opt]) = "%box_float"
-  external of_float : (float[@local_opt]) -> float# = "%unbox_float"
-
-  val ( + ) : float# -> float# -> float#
-  val ( - ) : float# -> float# -> float#
-  val ( * ) : float# -> float# -> float#
-  val ( / ) : float# -> float# -> float#
-  val ( ** ) : float# -> float# -> float#
-  val ( > ) : float# -> float# -> bool
+module Float_u = struct
+  include Stdlib__Float_u
+
+  let ( + ) = add
+  let ( - ) = sub
+  let ( * ) = mul
+  let ( / ) = div
+  let ( ** ) = pow
+  let ( > ) x y = (compare x y) > 0
 end
 
-module Float_u : Float_u = struct
-  external to_float : float# -> (float[@local_opt]) = "%box_float"
-  external of_float : (float[@local_opt]) -> float# = "%unbox_float"
-
-  (* We may in the future add primitives for these, but for now this has proven
-     to be good enough - the boxing/unboxing is eliminated on all
-     middle-ends. *)
-  let[@inline always] ( + ) x y = of_float ((to_float x) +. (to_float y))
-  let[@inline always] ( - ) x y = of_float ((to_float x) -. (to_float y))
-  let[@inline always] ( * ) x y = of_float ((to_float x) *. (to_float y))
-  let[@inline always] ( / ) x y = of_float ((to_float x) /. (to_float y))
-  let[@inline always] ( ** ) x y = of_float ((to_float x) ** (to_float y))
-  let[@inline always] ( > ) x y = (to_float x) > (to_float y)
-end
-
-(* CR layouts v2: move this into a stand-alone [Float_u] module *)
-
 (*********************************)
 (* Test 1: some basic arithmetic *)