--- ../ppx/coverage/instrument.ml
+++ ../ppx/coverage/instrument.ml
@@ -491,18 +491,10 @@
           | Pexp_fun (arg_label, default, pattern, body) ->
               let body = instrument_expression state body in
               Pexp_fun (arg_label, default, pattern, body)
-          | Pexp_function (params, constraint_, body) -> begin
-              match body with
-              | Pfunction_body body ->
-                  let body = instrument_expression state body in
-                  Pexp_function (params, constraint_, Pfunction_body body)
-              | Pfunction_cases (cases, loc, attrs) ->
-                  let cases =
-                    List.map cases ~f:(fun case ->
-                        { case with pc_rhs = instrument_expression state case.pc_rhs })
-                  in
-                  Pexp_function (params, constraint_, Pfunction_cases (cases, loc, attrs))
-            end
+          | Pexp_function cases ->
+              let cases =
+                List.map cases ~f:(fun case ->
+                    { case with pc_rhs = instrument_expression state case.pc_rhs })
+              in
+              Pexp_function cases
           | desc -> desc