diff --git a/lib/backend.ml b/lib/backend.ml
index b18ba16..c645fc5 100644
--- a/lib/backend.ml
+++ b/lib/backend.ml
@@ -147,12 +147,7 @@ module Benchmark_summary = struct
 end
 
 module Error_regression_result = struct
-  type t = {
-    sample_id : int;
-    merlin_id : int;
-    cmd : Merlin.Cmd.t;
-    success : bool;
-  }
+  type t = { sample_id : int; cmd : Merlin.Cmd.t; success : bool }
   [@@deriving yojson_of]
 
   (* FIXME: print the sample repeats in a separate json field *)
@@ -395,7 +390,7 @@ module Error_regression = struct
       ~query_type:_ tables =
     let resp =
       let success = List.for_all Merlin.Response.is_successful responses in
-      { Error_regression_result.sample_id = id; success; cmd; merlin_id }
+      { Error_regression_result.sample_id = id; success; cmd }
     in
     let cmd = { Command.sample_id = id; cmd; merlin_id } in
     tables.results <- resp :: tables.results;
diff --git a/test/error_regression.t/run.t b/test/error_regression.t/run.t
index 7ff4a89..67db75e 100644
--- a/test/error_regression.t/run.t
+++ b/test/error_regression.t/run.t
@@ -7,13 +7,13 @@ TODO     stderr:
   $ merl-an error-regression -s 1 -p test.ml,test1.ml --data=test-data 2>/dev/null
 
   $ cat test-data/results.json
-  {"sample_id":13,"merlin_id":0,"cmd":"ocamlmerlin server errors -filename test1.ml < test1.ml","success":true}
-  {"sample_id":12,"merlin_id":0,"cmd":" ocamlmerlin server locate -look-for ml -position '3:12' -index 0 -filename test1.ml < test1.ml","success":true}
-  {"sample_id":9,"merlin_id":0,"cmd":"ocamlmerlin server occurrences -identifier-at '3:12' -filename test1.ml < test1.ml","success":true}
-  {"sample_id":8,"merlin_id":0,"cmd":"ocamlmerlin server type-enclosing -position '1:8' -filename test1.ml < test1.ml","success":true}
-  {"sample_id":7,"merlin_id":0,"cmd":"ocamlmerlin server case-analysis -start '1:8' -end '1:8' -filename test1.ml < test1.ml","success":true}
-  {"sample_id":6,"merlin_id":0,"cmd":"ocamlmerlin server errors -filename test.ml < test.ml","success":true}
-  {"sample_id":5,"merlin_id":0,"cmd":" ocamlmerlin server locate -look-for ml -position '3:12' -index 0 -filename test.ml < test.ml","success":true}
-  {"sample_id":2,"merlin_id":0,"cmd":"ocamlmerlin server occurrences -identifier-at '3:12' -filename test.ml < test.ml","success":true}
-  {"sample_id":1,"merlin_id":0,"cmd":"ocamlmerlin server type-enclosing -position '3:12' -filename test.ml < test.ml","success":true}
-  {"sample_id":0,"merlin_id":0,"cmd":"ocamlmerlin server case-analysis -start '3:14' -end '3:14' -filename test.ml < test.ml","success":true}
+  {"sample_id":13,"cmd":"ocamlmerlin server errors -filename test1.ml < test1.ml","success":true}
+  {"sample_id":12,"cmd":" ocamlmerlin server locate -look-for ml -position '3:12' -index 0 -filename test1.ml < test1.ml","success":true}
+  {"sample_id":9,"cmd":"ocamlmerlin server occurrences -identifier-at '3:12' -filename test1.ml < test1.ml","success":true}
+  {"sample_id":8,"cmd":"ocamlmerlin server type-enclosing -position '1:8' -filename test1.ml < test1.ml","success":true}
+  {"sample_id":7,"cmd":"ocamlmerlin server case-analysis -start '1:8' -end '1:8' -filename test1.ml < test1.ml","success":true}
+  {"sample_id":6,"cmd":"ocamlmerlin server errors -filename test.ml < test.ml","success":true}
+  {"sample_id":5,"cmd":" ocamlmerlin server locate -look-for ml -position '3:12' -index 0 -filename test.ml < test.ml","success":true}
+  {"sample_id":2,"cmd":"ocamlmerlin server occurrences -identifier-at '3:12' -filename test.ml < test.ml","success":true}
+  {"sample_id":1,"cmd":"ocamlmerlin server type-enclosing -position '3:12' -filename test.ml < test.ml","success":true}
+  {"sample_id":0,"cmd":"ocamlmerlin server case-analysis -start '3:14' -end '3:14' -filename test.ml < test.ml","success":true}