diff --git a/ocaml/tests/dune b/ocaml/tests/dune
index 7cc177ba586..0b3c93ed3ca 100644
--- a/ocaml/tests/dune
+++ b/ocaml/tests/dune
@@ -7,7 +7,7 @@
       test_cluster_host test_cluster test_pusb test_network_sriov
       test_client test_valid_ref_list suite_alcotest_server
       test_vm_placement test_vm_helpers test_repository test_repository_helpers
-      test_ref test_vm_group
+      test_ref test_xapi_helpers test_vm_group
       test_livepatch test_rpm test_updateinfo test_storage_smapiv1_wrapper test_storage_quicktest test_observer
       test_pool_periodic_update_sync test_pkg_mgr))
   (libraries
@@ -79,13 +79,15 @@
 (tests
   (names test_vm_helpers test_vm_placement test_network_sriov test_vdi_cbt
     test_clustering test_pusb test_daemon_manager test_repository test_repository_helpers
-    test_livepatch test_rpm test_updateinfo test_pool_periodic_update_sync test_pkg_mgr)
+    test_livepatch test_rpm test_updateinfo test_pool_periodic_update_sync test_pkg_mgr
+    test_xapi_helpers)
   (package xapi)
   (modes exe)
   (modules test_vm_helpers test_vm_placement test_network_sriov test_vdi_cbt
     test_event test_clustering test_cluster_host test_cluster test_pusb
     test_daemon_manager test_repository test_repository_helpers test_livepatch test_rpm
-    test_updateinfo test_pool_periodic_update_sync test_pkg_mgr)
+    test_updateinfo test_pool_periodic_update_sync test_pkg_mgr
+    test_xapi_helpers)
   (libraries
     alcotest
     fmt
diff --git a/ocaml/tests/test_xapi_helpers.ml b/ocaml/tests/test_xapi_helpers.ml
new file mode 100644
index 00000000000..172e5c6e6a1
--- /dev/null
+++ b/ocaml/tests/test_xapi_helpers.ml
@@ -0,0 +1,45 @@
+(*
+ * Copyright (C) Cloud Software Group, Inc
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; version 2.1 only. with the special
+ * exception on linking described in file LICENSE.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *)
+
+let strings =
+  [
+    ("foobar", "foobar")
+  ; ("foobarproxy_username=password", "foobarproxy_username=(filtered)")
+  ; ("barfooproxy_password=secret", "barfooproxy_password=(filtered)")
+  ; ("password", "password")
+  ; ("username=password", "username=password")
+  ; ("password=password", "password=password")
+  ; ("proxy_username=", "proxy_username=(filtered)")
+  ]
+
+let filtering_test =
+  List.map
+    (fun (input, expected) ->
+      let test_filtering () =
+        let filtered =
+          match Helpers.filter_args [input] with x :: _ -> x | _ -> ""
+        in
+        Printf.printf "%s\n" input ;
+        Alcotest.(check string) "secrets must be filtered out" expected filtered
+      in
+      ( Printf.sprintf {|Validation of argument filtering of "%s"|} input
+      , `Quick
+      , test_filtering
+      )
+    )
+    strings
+
+let () =
+  Suite_init.harness_init () ;
+  Alcotest.run "Test XAPI Helpers suite" [("Test_xapi_helpers", filtering_test)]
diff --git a/ocaml/xapi/helpers.ml b/ocaml/xapi/helpers.ml
index 4d3cb36ebdd..e782bec8991 100644
--- a/ocaml/xapi/helpers.ml
+++ b/ocaml/xapi/helpers.ml
@@ -42,21 +42,15 @@ let log_exn_continue msg f x =
 type log_output = Always | Never | On_failure
 
 let filter_patterns =
-  [
-    ( Re.Str.regexp "^\\(.*proxy_\\(username\\|password\\)=\\)\\(.*\\)$"
-    , "\\1(filtered)"
-    )
-  ]
+  [(Re.Pcre.regexp "^(.*proxy_(username|password)=)(.*)$", "(filtered)")]
 
 let filter_args args =
   List.map
     (fun arg ->
       List.fold_left
         (fun acc (r, t) ->
-          if Re.Str.string_match r acc 0 then
-            Re.Str.replace_matched t acc
-          else
-            acc
+          try String.concat "" [(Re.Pcre.extract ~rex:r acc).(1); t]
+          with Not_found -> acc
         )
         arg filter_patterns
     )