diff --git a/lib/bookbinder/dita_command_creator.rb b/lib/bookbinder/dita_command_creator.rb
index f98bf203b..f45bc264b 100644
--- a/lib/bookbinder/dita_command_creator.rb
+++ b/lib/bookbinder/dita_command_creator.rb
@@ -34,12 +34,19 @@ def unduplicated_flags(write_to: nil, ditamap_path: nil, ditaval_path: nil, dita
       arg_flags = {
           'output.dir' => write_to,
           'args.input' => ditamap_path,
-          'args.filter' => ditaval_path || ""
-      }
+      }.merge(filter(ditaval_path))
       all_flags = arg_flags.merge(base_flags.merge(optional_flags dita_flags))
       format(all_flags)
     end
 
+    def filter(ditaval_path)
+      if ditaval_path
+        { 'args.filter' => ditaval_path }
+      else
+        {}
+      end
+    end
+
     def base_flags
       {
           'basedir' => '/',
diff --git a/spec/lib/bookbinder/dita_command_creator_spec.rb b/spec/lib/bookbinder/dita_command_creator_spec.rb
index f886fcb28..90b5c94f8 100644
--- a/spec/lib/bookbinder/dita_command_creator_spec.rb
+++ b/spec/lib/bookbinder/dita_command_creator_spec.rb
@@ -115,7 +115,6 @@ module Bookbinder
                   'ant -f /path/to/dita/ot ' +
                   "-Doutput.dir='/path/to/processed/dita/boo' " +
                   "-Dargs.input='/local/path/to/repo/path/to/map.ditamap' " +
-                  "-Dargs.filter='' " +
                   "-Dbasedir='/' " +
                   "-Dtranstype='tocjs' " +
                   "-Ddita.temp.dir='hey/some/new/dir' " +
@@ -144,7 +143,6 @@ module Bookbinder
       'ant -f /path/to/dita/ot ' +
       "-Doutput.dir='/path/to/processed/dita/boo' " +
       "-Dargs.input='/local/path/to/repo/path/to/map.ditamap' " +
-      "-Dargs.filter='' " +
       "-Dbasedir='/' " +
       "-Dtranstype='tocjs' " +
       "-Ddita.temp.dir='/tmp/bookbinder_dita' " +