diff --git a/src/convert/flags.rs b/src/convert/flags.rs
index 1c048f2..21540ed 100644
--- a/src/convert/flags.rs
+++ b/src/convert/flags.rs
@@ -37,23 +37,25 @@ impl FlagConverter {
         return Ok(());
     }
 
-    fn write_list_flag(&self, pfx: &str, name: &str, v: &Val, w: &mut Write) -> Result<()> {
-        if let &Val::List(ref def) = v {
-            // first of all we need to make sure that each &Val is only a primitive type.
-            for v in def.iter() {
-                let vref = v.as_ref();
-                if vref.is_list() || vref.is_tuple() || vref.is_macro() {
-                    eprintln!(
-                        "Skipping non primitive val in list for flag {}{}",
-                        pfx, name
-                    );
-                } else {
-                    try!(self.write_flag_name(pfx, name, w));
-                    try!(self.write(pfx, vref, w));
-                }
+    fn write_list_flag(
+        &self,
+        pfx: &str,
+        name: &str,
+        def: &Vec<Rc<Val>>,
+        w: &mut Write,
+    ) -> Result<()> {
+        // first of all we need to make sure that each &Val is only a primitive type.
+        for v in def.iter() {
+            let vref = v.as_ref();
+            if vref.is_list() || vref.is_tuple() || vref.is_macro() {
+                eprintln!(
+                    "Skipping non primitive val in list for flag {}{}",
+                    pfx, name
+                );
+            } else {
+                try!(self.write_flag_name(pfx, name, w));
+                try!(self.write(pfx, vref, w));
             }
-        } else {
-            panic!("Impossible call happened. Somebody messed up.")
         }
         return Ok(());
     }
@@ -82,14 +84,18 @@ impl FlagConverter {
                     try!(self.write_flag_name(pfx, &name.val, w));
                     continue;
                 }
-                if val.is_tuple() {
-                    let new_pfx = format!("{}{}.", pfx, name);
-                    try!(self.write(&new_pfx, val, w));
-                } else if val.is_list() {
-                    try!(self.write_list_flag(pfx, &name.val, &val, w));
-                } else {
-                    try!(self.write_flag_name(pfx, &name.val, w));
-                    try!(self.write(pfx, &val, w));
+                match val.as_ref() {
+                    &Val::Tuple(_) => {
+                        let new_pfx = format!("{}{}.", pfx, name);
+                        try!(self.write(&new_pfx, val, w));
+                    }
+                    &Val::List(ref def) => {
+                        try!(self.write_list_flag(pfx, &name.val, def, w));
+                    }
+                    _ => {
+                        try!(self.write_flag_name(pfx, &name.val, w));
+                        try!(self.write(pfx, &val, w));
+                    }
                 }
             },
             &Val::Macro(ref _def) => {