diff --git a/src/gmser_dyn.erl b/src/gmser_dyn.erl
index 8bb0930..a39843c 100644
--- a/src/gmser_dyn.erl
+++ b/src/gmser_dyn.erl
@@ -797,6 +797,7 @@ dynamic_types_test_() ->
     [ ?_test(revert_to_default_types())
     , ?_test(t_typed_map())
     , ?_test(t_alts())
+    , ?_test(t_switch())
     , ?_test(t_anyints())
     , ?_test(t_missing_labels())
     ].
@@ -920,6 +921,14 @@ t_alts() ->
     t_round_trip_typed(#{alt => [negint, int]}, 4),
     ok.
 
+t_switch() ->
+    T = #{switch => #{a => int, b => binary}},
+    t_round_trip_typed(T, #{a => 17}),
+    t_round_trip_typed(T, #{b => <<"foo">>}),
+    ?assertError({illegal,int,<<"foo">>}, encode_typed(T, #{a => <<"foo">>})),
+    MMap = #{a => 17, b => <<"foo">>},
+    ?assertError({illegal, singleton_map, MMap}, encode_typed(T, MMap)).
+
 t_anyints() ->
     t_round_trip_typed(anyint, -5),
     t_round_trip_typed(anyint, 5),
@@ -947,7 +956,7 @@ t_new_version() ->
     Types2 = types_from_list([{vsn, V2},
                               {modify, {msg1, {int, int, int}}}], Types1),
     Enc21 = encode_typed(msg1, T2, Types1),
-    try encode_typed(msg1, T2, Types2) catch error:_ -> ok end,
+    ?assertError({illegal,{int,int,int},T2}, encode_typed(msg1, T2, Types2)),
     T3 = {3,5,7},
     Enc32 = encode_typed(msg1, T3, Types2),
     T3 = decode(Enc32, Types2).