diff --git a/asmcomp/asmgen.ml b/asmcomp/asmgen.ml
index c3bd1cb55..99e7dbe0d 100644
--- a/asmcomp/asmgen.ml
+++ b/asmcomp/asmgen.ml
@@ -27,8 +27,7 @@ type error = Assembler_error of string
 
 exception Error of error
 
-let liveness ppf phrase =
-  Liveness.fundecl ppf phrase; phrase
+let liveness phrase = Liveness.fundecl phrase; phrase
 
 let dump_if ppf flag message phrase =
   if !flag then Printmach.phase message ppf phrase
@@ -96,7 +95,7 @@ let rec regalloc ppf round fd =
   let (newfd, redo_regalloc) = Reload.fundecl fd in
   dump_if ppf dump_reload "After insertion of reloading code" newfd;
   if redo_regalloc then begin
-    Reg.reinit(); Liveness.fundecl ppf newfd; regalloc ppf (round + 1) newfd
+    Reg.reinit(); Liveness.fundecl newfd; regalloc ppf (round + 1) newfd
   end else newfd
 
 let (++) x f = f x
@@ -111,15 +110,15 @@ let compile_fundecl (ppf : formatter) fd_cmm =
   ++ pass_dump_if ppf dump_combine "After allocation combining"
   ++ Profile.record ~accumulate:true "cse" CSE.fundecl
   ++ pass_dump_if ppf dump_cse "After CSE"
-  ++ Profile.record ~accumulate:true "liveness" (liveness ppf)
+  ++ Profile.record ~accumulate:true "liveness" liveness
   ++ Profile.record ~accumulate:true "deadcode" Deadcode.fundecl
   ++ pass_dump_if ppf dump_live "Liveness analysis"
   ++ Profile.record ~accumulate:true "spill" Spill.fundecl
-  ++ Profile.record ~accumulate:true "liveness" (liveness ppf)
+  ++ Profile.record ~accumulate:true "liveness" liveness
   ++ pass_dump_if ppf dump_spill "After spilling"
   ++ Profile.record ~accumulate:true "split" Split.fundecl
   ++ pass_dump_if ppf dump_split "After live range splitting"
-  ++ Profile.record ~accumulate:true "liveness" (liveness ppf)
+  ++ Profile.record ~accumulate:true "liveness" liveness
   ++ Profile.record ~accumulate:true "regalloc" (regalloc ppf 1)
   ++ Profile.record ~accumulate:true "available_regs" Available_regs.fundecl
   ++ Profile.record ~accumulate:true "linearize" Linearize.fundecl
diff --git a/asmcomp/liveness.ml b/asmcomp/liveness.ml
index 9791e8c5c..28c5868c3 100644
--- a/asmcomp/liveness.ml
+++ b/asmcomp/liveness.ml
@@ -160,7 +160,7 @@ let reset () =
   live_at_raise := Reg.Set.empty;
   live_at_exit := []
 
-let fundecl ppf f =
+let fundecl f =
   let initially_live = live f.fun_body Reg.Set.empty in
   (* Sanity check: only function parameters (and the Spacetime node hole
      register, if profiling) can be live at entrypoint *)
@@ -170,6 +170,6 @@ let fundecl ppf f =
     else Reg.Set.remove Proc.loc_spacetime_node_hole wrong_live
   in
   if not (Reg.Set.is_empty wrong_live) then begin
-    Format.fprintf ppf "%a@." Printmach.regset wrong_live;
-    Misc.fatal_error "Liveness.fundecl"
+    Misc.fatal_errorf "@[Liveness.fundecl:@\n%a@]"
+      Printmach.regset wrong_live
   end
diff --git a/asmcomp/liveness.mli b/asmcomp/liveness.mli
index 7a8fae627..37f5c170b 100644
--- a/asmcomp/liveness.mli
+++ b/asmcomp/liveness.mli
@@ -16,7 +16,5 @@
 (* Liveness analysis.
    Annotate mach code with the set of regs live at each point. *)
 
-open Format
-
 val reset : unit -> unit
-val fundecl: formatter -> Mach.fundecl -> unit
+val fundecl: Mach.fundecl -> unit