diff --git a/Lib/gettext.py b/Lib/gettext.py
index 724cecb..578490f 100644
--- a/Lib/gettext.py
+++ b/Lib/gettext.py
@@ -235,7 +235,11 @@
         raise IOError(ENOENT, 'No translation file found for domain', domain)
     key = os.path.abspath(mofile)
     # TBD: do we need to worry about the file pointer getting collected?
-    t = _translations.setdefault(key, class_(open(mofile, 'rb')))
+    # Avoid opening, reading, and parsing the .mo file after it's been done
+    # once.
+    t = _translations.get(key)
+    if t is None:
+        t = _translations.setdefault(key, class_(open(mofile, 'rb')))
     return t