diff --git a/data/tools/unit_tree/helpers.py b/data/tools/unit_tree/helpers.py
index 19bc0773e38..c1d7dfc0b5f 100644
--- a/data/tools/unit_tree/helpers.py
+++ b/data/tools/unit_tree/helpers.py
@@ -11,11 +11,11 @@ class ParserWithCoreMacros:
     """
     A wrapper around the WML parser to do some things like we want.
     """
-    def __init__(self, isocode, datadir, userdir):
+    def __init__(self, isocode, datadir, userdir, transdir):
         self.datadir = datadir
         self.userdir = userdir
         # Handle translations.
-        self.translations = wmltools.Translations()
+        self.translations = wmltools.Translations(transdir)
         def gettext(textdomain, x):
             return self.translations.get(textdomain, isocode, x, x)
         self.gettext = gettext
@@ -134,14 +134,14 @@ class WesnothList:
     """
     Lists various Wesnoth stuff like units, campaigns, terrains, factions...
     """
-    def __init__(self, isocode, datadir, userdir):
+    def __init__(self, isocode, datadir, userdir, transdir):
         self.unit_lookup = {}
         self.race_lookup = {}
         self.terrain_lookup = {}
         self.movetype_lookup = {}
         self.era_lookup = {}
         self.campaign_lookup = {}
-        self.parser = ParserWithCoreMacros(isocode, datadir, userdir)
+        self.parser = ParserWithCoreMacros(isocode, datadir, userdir, transdir)
 
     def add_terrains(self):
         """
diff --git a/data/tools/wesnoth/wmltools.py b/data/tools/wesnoth/wmltools.py
index 79799de700d..9509f41e896 100644
--- a/data/tools/wesnoth/wmltools.py
+++ b/data/tools/wesnoth/wmltools.py
@@ -633,7 +633,12 @@ class Translation(dict):
                 return key[key.find("^") + 1:]
             return "?"
         else:
-            return self.gettext.get(key, dflt)
+            t = self.gettext.get(key, dflt)
+            if not t:
+                if key:
+                    return key[key.find("^") + 1:]
+                return "?"
+            return t
     def __getitem__(self, key):
         if self.isocode == "C":
             return key
diff --git a/data/tools/wmlunits b/data/tools/wmlunits
index e5d19bb83e6..f184d670d77 100755
--- a/data/tools/wmlunits
+++ b/data/tools/wmlunits
@@ -692,7 +692,7 @@ def output(isocode):
     """
     print "WML parser language reset to %s." % isocode
 
-    stuff = helpers.WesnothList(isocode, datadir, userdir)
+    stuff = helpers.WesnothList(isocode, datadir, userdir, transdir)
 
     # Parse some stuff we may need.
     print "Parsing terrains ...",
@@ -786,6 +786,8 @@ if __name__ == '__main__':
         help = "Specify Wesnoth's data to use. Default is to search current directory upwards.")
     op.add_option("-u", "--userdir",
         help = "Specify user data dir to use, which is automatically scanned for addons. For example -u ~/.wesnoth/data")
+    op.add_option("-t", "--transdir",
+        help = "Specify directory which has a po subfolder for translations.")
     options, args = op.parse_args()
 
     if not options.output:
@@ -801,6 +803,10 @@ if __name__ == '__main__':
         datadir = options.datadir
 
     userdir = options.userdir
+    if options.transdir:
+        transdir = options.transdir
+    else:
+        transdir = os.path.dirname(datadir)
     
     if options.language == "all":
         languages = find_languages().keys()