diff --git a/beets/util/confit.py b/beets/util/confit.py
index cd8c7f61d..cf8b36296 100644
--- a/beets/util/confit.py
+++ b/beets/util/confit.py
@@ -794,7 +794,9 @@ class Configuration(RootView):
             appdir = os.environ[self._env_var]
             appdir = os.path.abspath(os.path.expanduser(appdir))
             if os.path.isfile(appdir):
-                raise ConfigError('%s must be a directory' % self._env_var)
+                raise ConfigError('{0} must be a directory'.format(
+                    self._env_var
+                ))
 
         else:
             # Search platform-specific locations. If no config file is
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 5e0411da8..6d1e06fdc 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -27,6 +27,8 @@ Fixes:
   with quotation marks in their names. Thanks again to Pedro Silva.
 * Fix a crash when importing with both of the :ref:`group_albums` and
   :ref:`incremental` options enabled. Thanks to geigerzaehler.
+* Give a sensible error message when ``BEETSDIR`` points to a file. Thanks
+  again to geigerzaehler.
 
 
 1.3.3 (February 26, 2014)