diff --git a/sphinx/builders/gettext.py b/sphinx/builders/gettext.py
index 81535f97f..b64c917ca 100644
--- a/sphinx/builders/gettext.py
+++ b/sphinx/builders/gettext.py
@@ -76,7 +76,8 @@ class I18nBuilder(Builder):
         return
 
     def write_doc(self, docname, doctree):
-        catalog = self.catalogs[find_catalog(docname, self.config)]
+        catalog = self.catalogs[find_catalog(docname,
+                                             self.config.gettext_compact)]
 
         for node, msg in extract_messages(doctree):
             catalog.add(msg, node)
diff --git a/sphinx/environment.py b/sphinx/environment.py
index 302d8766f..ae353ad44 100644
--- a/sphinx/environment.py
+++ b/sphinx/environment.py
@@ -41,7 +41,7 @@ from sphinx.util import url_re, get_matching_docs, docname_join, split_into, \
      FilenameUniqDict
 from sphinx.util.nodes import clean_astext, make_refnode, extract_messages, \
      WarningStream
-from sphinx.util.osutil import movefile, SEP, ustrftime
+from sphinx.util.osutil import movefile, SEP, ustrftime, find_catalog
 from sphinx.util.matching import compile_matchers
 from sphinx.util.pycompat import all, class_types
 from sphinx.util.websupport import is_commentable
@@ -198,13 +198,15 @@ class Locale(Transform):
         settings, source = self.document.settings, self.document['source']
         # XXX check if this is reliable
         assert source.startswith(env.srcdir)
-        docname = os.path.splitext(source[len(env.srcdir):].lstrip(os.sep))[0]
-        section = docname.split(os.sep, 1)[0]
+        docname = path.splitext(path.relpath(source, env.srcdir))[0]
+        textdomain = find_catalog(docname,
+                                  self.document.settings.gettext_compact)
 
         # fetch translations
-        dirs = [path.join(env.srcdir, x)
-                for x in env.config.locale_dirs]
-        catalog, has_catalog = init_locale(dirs, env.config.language, section)
+        dirs = [path.join(env.srcdir, directory)
+                for directory in env.config.locale_dirs]
+        catalog, has_catalog = init_locale(dirs, env.config.language,
+                                           textdomain)
         if not has_catalog:
             return
 
@@ -708,6 +710,7 @@ class BuildEnvironment:
         self.settings['input_encoding'] = self.config.source_encoding
         self.settings['trim_footnote_reference_space'] = \
             self.config.trim_footnote_reference_space
+        self.settings['gettext_compact'] = self.config.gettext_compact
 
         self.patch_lookup_functions()
 
diff --git a/sphinx/util/osutil.py b/sphinx/util/osutil.py
index e37d23954..ee6a6c858 100644
--- a/sphinx/util/osutil.py
+++ b/sphinx/util/osutil.py
@@ -141,5 +141,5 @@ def safe_relpath(path, start=None):
     except ValueError:
         return path
 
-def find_catalog(docname, config):
-    return docname.split(SEP, 1)[0] if config.gettext_compact else docname
+def find_catalog(docname, compaction):
+    return docname.split(SEP, 1)[0] if compaction else docname