diff --git a/src/hz.erl b/src/hz.erl
index 1fec2c3..27a22cf 100644
--- a/src/hz.erl
+++ b/src/hz.erl
@@ -1453,7 +1453,7 @@ convert_function_spec(#{name := NameBin, arguments := Args, returns := Result})
 
 convert_arg(#{name := NameBin, type := TypeDef}) ->
     Name = binary_to_list(NameBin),
-    {ok, Type} = opaque_type([], TypeDef),
+    Type = opaque_type([], TypeDef),
     {Name, Type}.
 
 convert_namespace_typedefs(#{namespace := NS}) ->
@@ -1561,7 +1561,7 @@ opaque_type_name(Name)           -> binary_to_list(Name).
 annotate_function_specs([], _Types, Specs) ->
     Specs;
 annotate_function_specs([{Name, ArgsOpaque, ResultOpaque} | Rest], Types, Specs) ->
-    {ok, Args} = annotate_types(ArgsOpaque, Types, []),
+    {ok, Args} = annotate_bindings(ArgsOpaque, Types, []),
     {ok, Result} = annotate_type(ResultOpaque, Types),
     NewSpecs = maps:put(Name, {Args, Result}, Specs),
     annotate_function_specs(Rest, Types, NewSpecs).
@@ -2358,3 +2358,14 @@ state_coerce_test() ->
     {ok, {[], Output}} = aaci_lookup_spec(AACI, "init"),
     try_coerce(Output, 0, 0).
 
+param_test() ->
+    Contract = "
+        contract C =
+            type state = int
+            entrypoint init(x): state = x
+    ",
+    {ok, AACI} = aaci_from_string(Contract),
+    {ok, {[{"x", Input}], Output}} = aaci_lookup_spec(AACI, "init"),
+    try_coerce(Input, 0, 0),
+    try_coerce(Output, 0, 0).
+