diff --git a/src/domains/access.ml b/src/domains/access.ml
index 83903ba355..fa6446df16 100644
--- a/src/domains/access.ml
+++ b/src/domains/access.ml
@@ -16,8 +16,8 @@ let is_ignorable_type (t: typ): bool =
   | TComp ({ cname = "__pthread_mutex_s" | "__pthread_rwlock_arch_t" | "__jmp_buf_tag" | "_pthread_cleanup_buffer" | "__pthread_cleanup_frame" | "__cancel_jmp_buf_tag"; _}, _) -> true
   | TComp ({ cname; _}, _) when String.starts_with_stdlib ~prefix:"__anon" cname ->
     begin match Cilfacade.split_anoncomp_name cname with
-      | (true, ("__once_flag" | "__pthread_unwind_buf_t" | "__cancel_jmp_buf"), _) -> true (* anonstruct *)
-      | (false, ("pthread_mutexattr_t" | "pthread_condattr_t" | "pthread_barrierattr_t"), _) -> true (* anonunion *)
+      | (true, Some ("__once_flag" | "__pthread_unwind_buf_t" | "__cancel_jmp_buf"), _) -> true (* anonstruct *)
+      | (false, Some ("pthread_mutexattr_t" | "pthread_condattr_t" | "pthread_barrierattr_t"), _) -> true (* anonunion *)
       | _ -> false
     end
   | TComp ({ cname = "lock_class_key"; _ }, _) -> true
diff --git a/src/util/cilfacade.ml b/src/util/cilfacade.ml
index c77d2cd738..f0ac3202ce 100644
--- a/src/util/cilfacade.ml
+++ b/src/util/cilfacade.ml
@@ -342,22 +342,23 @@ let makeBinOp binop e1 e2 =
   let (_, e) = Cabs2cil.doBinOp binop e1 t1 e2 t2 in
   e
 
-let anoncomp_name_regexp = Str.regexp {|^__anon\(struct\|union\)_\(.+\)_\([0-9]+\)$|}
+let anoncomp_name_regexp = Str.regexp {|^__anon\(struct\|union\)\(_\(.+\)\)?_\([0-9]+\)$|}
 
 let split_anoncomp_name name =
   (* __anonunion_pthread_mutexattr_t_488594144 *)
+  (* __anonunion_50 *)
   if Str.string_match anoncomp_name_regexp name 0 then (
     let struct_ = match Str.matched_group 1 name with
       | "struct" -> true
       | "union" -> false
       | _ -> assert false
     in
-    let name' = Str.matched_group 2 name in
-    let id = int_of_string (Str.matched_group 3 name) in
+    let name' = try Some (Str.matched_group 3 name) with Not_found -> None in
+    let id = int_of_string (Str.matched_group 4 name) in
     (struct_, name', id)
   )
   else
-    invalid_arg "Cilfacade.split_anoncomp_name"
+    invalid_arg ("Cilfacade.split_anoncomp_name: " ^ name)
 
 (** Pretty-print typsig like typ, because
     {!d_typsig} prints with CIL constructors. *)
diff --git a/unittest/mainTest.ml b/unittest/mainTest.ml
index df67340309..642e495d50 100644
--- a/unittest/mainTest.ml
+++ b/unittest/mainTest.ml
@@ -8,6 +8,7 @@ let all_tests = ("" >:::
     LvalTest.test ();
     CompilationDatabaseTest.tests;
     LibraryDslTest.tests;
+    CilfacadeTest.tests;
     (* etc *)
     "domaintest" >::: QCheck_ounit.to_ounit2_test_list Maindomaintest.all_testsuite;
     IntOpsTest.tests;
diff --git a/unittest/util/cilfacadeTest.ml b/unittest/util/cilfacadeTest.ml
new file mode 100644
index 0000000000..482a502824
--- /dev/null
+++ b/unittest/util/cilfacadeTest.ml
@@ -0,0 +1,14 @@
+open Goblint_lib
+open OUnit2
+open Cilfacade
+
+let test_split_anoncomp_name _ =
+  let assert_equal = assert_equal ~printer:[%show: bool * string option * int] in
+  assert_equal (false, Some "pthread_mutexattr_t", 488594144) (split_anoncomp_name "__anonunion_pthread_mutexattr_t_488594144");
+  assert_equal (true, Some "__once_flag", 1234) (split_anoncomp_name "__anonstruct___once_flag_1234");
+  assert_equal (false, None, 50) (split_anoncomp_name "__anonunion_50")
+
+let tests =
+  "cilfacadeTest" >::: [
+    "split_anoncomp_name" >:: test_split_anoncomp_name;
+  ]