--- a/pvl/dns/process.py	Tue Mar 03 12:09:22 2015 +0200
+++ b/pvl/dns/process.py	Tue Mar 03 12:14:22 2015 +0200
@@ -35,30 +35,28 @@
         else:
             yield rr
 
-def zone_includes_path (rrs, includes_path):
+def zone_includes (rrs, includes_path,
+        include_trace=None,
+):
     """
         Rewrite include paths in zones.
+
+            include_trace           - append included paths to given list
     """
 
     for rr in rrs:
         if isinstance(rr, zone.ZoneDirective) and rr.directive == 'INCLUDE':
             include_path, = rr.arguments
 
-            yield zone.ZoneDirective.INCLUDE(os.path.join(includes_path, include_path))
+            include = os.path.join(includes_path, include_path)
+
+            if include_trace is not None:
+                include_trace.append(include)
+
+            yield zone.ZoneDirective.INCLUDE(include)
         else:
             yield rr
 
-def zone_includes (rrs):
-    """
-        Extract $INCLUDE paths from zone.
-    """
-
-    for rr in rrs:
-        if isinstance(rr, pvl.dns.ZoneDirective) and rr.directive == 'INCLUDE':
-            include_path, = rr.arguments
-
-            yield include_path
-
 def apply_zone_output (options, zone):
     """
         Output given ZoneDirective/ZoneRecord items to the output file/stdout.