diff --git a/rebar.lock b/rebar.lock
index 5d15125..33c4ee2 100644
--- a/rebar.lock
+++ b/rebar.lock
@@ -1,4 +1,4 @@
 [{<<"damsel">>,
   {git,"https://github.com/valitydev/damsel.git",
-       {ref,"dac2cb599499cc0701e60856f4092c9ab283eedf"}},
+       {ref,"38a420da68166d876153ea9d5e8701f636c11a0e"}},
   0}].
diff --git a/src/payproc_errors.erl b/src/payproc_errors.erl
index 43a19e6..d87dc87 100644
--- a/src/payproc_errors.erl
+++ b/src/payproc_errors.erl
@@ -81,10 +81,10 @@ sub_error_to_static(Type, #domain_SubFailure{code = Code, sub = SDE}) ->
 to_static(Code, Type, SDE) ->
     StaticCode = code_to_static(Code),
     case type_by_field(StaticCode, Type) of
-        SubType when SubType =/= undefined ->
-            {StaticCode, sub_error_to_static(SubType, SDE)};
-        undefined ->
-            {{unknown_error, Code}, #payproc_error_GeneralFailure{}}
+        SubType when SubType =:= undefined orelse SubType =:= unknown_error ->
+            {{unknown_error, Code}, sub_error_to_static(undefined, SDE)};
+        SubType ->
+            {StaticCode, sub_error_to_static(SubType, SDE)}
     end.
 
 -spec code_to_static(dynamic_code()) -> static_code().
@@ -148,6 +148,10 @@ join(Code, Sub) -> [Code, $:, Sub].
 %%
 
 -spec type_by_field(static_code(), type()) -> atom() | undefined.
+type_by_field(_Code, undefined) ->
+    undefined;
+type_by_field({unknown_error, _DynamicCode}, _Type) ->
+    unknown_error;
 type_by_field(Code, Type) ->
     case [Field || Field = {FCode, _} <- struct_info(Type), Code =:= FCode] of
         [{_, SubType}] -> SubType;
diff --git a/test/payproc_errors_SUITE.erl b/test/payproc_errors_SUITE.erl
index 0363305..99790c0 100644
--- a/test/payproc_errors_SUITE.erl
+++ b/test/payproc_errors_SUITE.erl
@@ -6,8 +6,9 @@
 -export([all/0]).
 
 -export([known_error_test/1]).
--export([unknown_error_test/1]).
 -export([unknown_error_atom_test/1]).
+-export([unknown_error_nested_test/1]).
+-export([unknown_error_nested_mixed_test/1]).
 -export([bad_static_type_test/1]).
 -export([formatting_test/1]).
 -export([from_notation_test/1]).
@@ -23,8 +24,9 @@
 all() ->
     [
         known_error_test,
-        unknown_error_test,
         unknown_error_atom_test,
+        unknown_error_nested_test,
+        unknown_error_nested_mixed_test,
         bad_static_type_test,
         formatting_test,
         from_notation_test,
@@ -62,16 +64,55 @@ unknown_error_atom_test(_C) ->
     DE = payproc_errors:construct('PaymentFailure', SE),
     ok = payproc_errors:match('PaymentFailure', DE, fun(E) when SE =:= E -> ok end).
 
--spec unknown_error_test(config()) -> _.
-unknown_error_test(_C) ->
-    UnknownCode = erlang:atom_to_binary(bad_error_code, utf8),
+-define(NESTED_UNKNOWN_SUBCODES,
+    {
+        {unknown_error, <<"rejected_routes">>},
+        {{unknown_error, <<"limit_hold_reject">>}, #payproc_error_GeneralFailure{}}
+    }
+).
+
+-spec unknown_error_nested_test(config()) -> _.
+unknown_error_nested_test(_C) ->
+    %% NOTE Ensure atoms exist
+    _ = rejected_routes,
+    _ = limit_hold_reject,
+
     DE = #domain_Failure{
-        code = UnknownCode
+        code = <<"forbidden">>,
+        sub = #domain_SubFailure{
+            code = <<"rejected_routes">>,
+            sub = #domain_SubFailure{
+                code = <<"limit_hold_reject">>
+            }
+        }
     },
-    SE = {{unknown_error, UnknownCode}, #payproc_error_GeneralFailure{}},
+    SE = {{unknown_error, <<"forbidden">>}, ?NESTED_UNKNOWN_SUBCODES},
     DE = payproc_errors:construct('PaymentFailure', SE),
     ok = payproc_errors:match('PaymentFailure', DE, fun(E) when SE =:= E -> ok end).
 
+-spec unknown_error_nested_mixed_test(config()) -> _.
+unknown_error_nested_mixed_test(_C) ->
+    %% NOTE Ensure atoms exist
+    _ = rejected_routes,
+    _ = limit_hold_reject,
+
+    DE = #domain_Failure{
+        code = <<"no_route_found">>,
+        sub = #domain_SubFailure{
+            code = <<"forbidden">>,
+            sub = #domain_SubFailure{
+                code = <<"rejected_routes">>,
+                sub = #domain_SubFailure{
+                    code = <<"limit_hold_reject">>
+                }
+            }
+        }
+    },
+    SE = {no_route_found, {{unknown_error, <<"forbidden">>}, ?NESTED_UNKNOWN_SUBCODES}},
+    EquivalentSE = {no_route_found, {forbidden, ?NESTED_UNKNOWN_SUBCODES}},
+    DE = payproc_errors:construct('PaymentFailure', SE),
+    ok = payproc_errors:match('PaymentFailure', DE, fun(E) when EquivalentSE =:= E -> ok end).
+
 -spec bad_static_type_test(config()) -> _.
 bad_static_type_test(_C) ->
     Bad = {qwe, #payproc_error_GeneralFailure{}},
@@ -87,6 +128,8 @@ bad_static_type_test(_C) ->
         (catch payproc_errors:construct('RefundFailure', {preauthorization_failed, #payproc_error_GeneralFailure{}})),
     {'EXIT', {badarg, _}} =
         (catch payproc_errors:construct('RefundFailure', Bad)),
+    {'EXIT', {badarg, _}} =
+        (catch payproc_errors:construct('PaymentFailure', {{unknown_error, <<"forbidden">>}, Bad})),
     ok.
 
 -spec formatting_test(config()) -> _.