diff --git a/infer/src/checkers/SimpleChecker.ml b/infer/src/checkers/SimpleChecker.ml
index 23fb535cf..74db23524 100644
--- a/infer/src/checkers/SimpleChecker.ml
+++ b/infer/src/checkers/SimpleChecker.ml
@@ -104,5 +104,5 @@ module Make (Spec : Spec) : S = struct
              Spec.report astate (ProcCfg.Exceptional.loc node) proc_name)
           astate_set in
     let inv_map = Analyzer.exec_pdesc (ProcData.make_default proc_desc tenv) in
-    Analyzer.M.iter do_reporting inv_map
+    Analyzer.InvariantMap.iter do_reporting inv_map
 end
diff --git a/infer/src/checkers/SimpleChecker.mli b/infer/src/checkers/SimpleChecker.mli
new file mode 100644
index 000000000..ecf5819a5
--- /dev/null
+++ b/infer/src/checkers/SimpleChecker.mli
@@ -0,0 +1,23 @@
+(*
+ * Copyright (c) 2016 - present Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *)
+
+module type Spec =
+sig
+  type astate
+  val initial : astate
+  val exec_instr :
+    astate ->
+    Sil.instr -> Cfg.Node.nodekind -> Procname.t -> Tenv.t -> astate
+  val report : astate -> Location.t -> Procname.t -> unit
+  val compare : astate -> astate -> int
+end
+
+module type S = sig val checker : Callbacks.proc_callback_args -> unit end
+
+module Make : functor (Spec : Spec) -> S
diff --git a/infer/src/checkers/registerCheckers.ml b/infer/src/checkers/registerCheckers.ml
index 19c019a4f..fbb0de5fe 100644
--- a/infer/src/checkers/registerCheckers.ml
+++ b/infer/src/checkers/registerCheckers.ml
@@ -41,6 +41,8 @@ let active_procedure_checkers () =
         AnnotationReachability.Interprocedural.check_and_report, checkers_enabled;
         ThreadSafety.method_analysis, false;
       ] in
+    (* make sure SimpleChecker.ml is not dead code *)
+    if false then (let module SC = SimpleChecker.Make in ());
     IList.map (fun (x, y) -> (x, y, Some Config.Java)) l in
   let c_cpp_checkers =
     let l =