diff --git a/binarycpython/utils/functions.py b/binarycpython/utils/functions.py
index f1ef1fad56e0b7e54d37c801d9c85f5a559b6217..4ffcabaa5d29ba81f5ac5aa86574cc9e50d6f12f 100644
--- a/binarycpython/utils/functions.py
+++ b/binarycpython/utils/functions.py
@@ -381,10 +381,10 @@ def create_arg_string(arg_dict, sort=False, filter_values=False):
     # 
     for key in keys:
         # Filter out NULLS (not compiled anyway)
-        if filter_values:
-            if not value in ["NULL", "Function"]:
+        if filter_values:   
+            if not arg_dict[key] in ["NULL", "Function"]:
                 if not value == "":
-                    default_dict[key] = value        
+                    arg_string += "{key} {value} ".format(key=key, value=arg_dict[key])
         else:
             arg_string += "{key} {value} ".format(key=key, value=arg_dict[key])
     arg_string = arg_string.strip()