diff --git a/src/Lean/Util/Profile.lean b/src/Lean/Util/Profile.lean
index d92d18fe5f..7b2c3314dc 100644
--- a/src/Lean/Util/Profile.lean
+++ b/src/Lean/Util/Profile.lean
@@ -9,9 +9,19 @@ import Lean.Data.Position
 namespace Lean
 
 /-- Print and accumulate run time of `act` when Option `profiler` is set to `true`. -/
-@[extern 5 "lean_lean_profileit"]
-constant profileit {α : Type} (category : @& String) (pos : @& Position) (act : IO α) : IO α := act
-def profileitPure {α : Type} (category : String) (pos : Position) (fn : Unit → α) : IO α :=
-profileit category pos $ IO.lazyPure fn
+@[extern "lean_profileit"]
+def profileit {α : Type} (category : @& String) (pos : @& Position) (fn : Unit → α) : α := fn ()
+
+unsafe def profileitIOUnsafe {ε α : Type} (category : String) (pos : Position) (act : EIO ε α) : EIO ε α :=
+  match profileit category pos fun _ => unsafeEIO act with
+  | Except.ok a    => pure a
+  | Except.error e => throw e
+
+@[implementedBy profileitIOUnsafe]
+def profileitIO {ε α : Type} (category : String) (pos : Position) (act : EIO ε α) : EIO ε α := act
+
+-- impossible to infer `ε`
+def profileitM {m : Type → Type} (ε : Type) [MonadFunctorT (EIO ε) (EIO ε) m m] {α : Type} (category : @& String) (pos : @& Position) (act : m α) : m α :=
+  monadMap (fun {β} => @profileitIO ε β category pos) act
 
 end Lean
diff --git a/src/library/time_task.cpp b/src/library/time_task.cpp
index 782f33561a..cf2e944352 100644
--- a/src/library/time_task.cpp
+++ b/src/library/time_task.cpp
@@ -64,13 +64,13 @@ time_task::~time_task() {
     }
 }
 
-/* profileit {α : Type} (category : string) (pos : position) (act : io α) : io α */
-extern "C" obj_res lean_lean_profileit(obj_arg, b_obj_arg category, b_obj_arg pos, obj_arg fn, obj_arg w) {
+/* profileit {α : Type} (category : String) (pos : Position) (fn : Unit → α) : α */
+extern "C" obj_res lean_profileit(b_obj_arg category, b_obj_arg pos, obj_arg fn) {
     time_task t(string_to_std(category),
-                message_builder(environment(), get_global_ios(), get_pos_info_provider()->get_file_name(),
+                message_builder(environment(), get_global_ios(), "foo",
                         pos_info(nat(cnstr_get(pos, 0), true).get_small_value(),
                                  nat(cnstr_get(pos, 1), true).get_small_value()),
                         message_severity::INFORMATION));
-    return apply_1(fn, w);
+    return apply_1(fn, box(0));
 }
 }