diff --git a/ext/hbsdctl.rb/hbsdctl.c b/ext/hbsdctl.rb/hbsdctl.c
index a7e662b..184d151 100644
--- a/ext/hbsdctl.rb/hbsdctl.c
+++ b/ext/hbsdctl.rb/hbsdctl.c
@@ -31,13 +31,16 @@ feature_set(VALUE self, VALUE path, VALUE state)
 {
   int r;
   char *cpath;
+  VALUE name;
 
   Check_Type(path, T_STRING);
   Check_Type(state, T_FIXNUM);
   cpath = RSTRING_PTR(path);
+  name = rb_funcall(self, rb_intern("name"), 0);
+  Check_Type(name, T_STRING);
   r = hbsdcontrol_set_feature_state(
     cpath,
-    RSTRING_PTR(rb_funcall(self, rb_intern("name"), 0)),
+    RSTRING_PTR(name),
     NUM2INT(state)
   );
   if (r == 0) {