diff --git a/fdroidserver/common.py b/fdroidserver/common.py
index c63a4aa1..388e3970 100644
--- a/fdroidserver/common.py
+++ b/fdroidserver/common.py
@@ -590,10 +590,13 @@ class vcs_bzr(vcs):
                 p.stdout.splitlines()]
 
 def retrieve_string(app_dir, string, xmlfiles=None):
+
+    res_dir = os.path.join(app_dir, 'res')
+
     if xmlfiles is None:
         xmlfiles = []
-        for r,d,f in os.walk(app_dir):
-            if r.endswith('/res/values'):
+        for r,d,f in os.walk(res_dir):
+            if r.endswith('/values'):
                 xmlfiles += [os.path.join(r,x) for x in f if x.endswith('.xml')]
 
     string_search = None