diff --git a/CHANGES b/CHANGES
index 5d3a7b809..23fc8cbd3 100644
--- a/CHANGES
+++ b/CHANGES
@@ -19,6 +19,8 @@ Changes in trunk
 * sphinx.htmlwriter: Make parsed-literal blocks work as expected,
   not highlighting them via Pygments.
 
+* sphinx.environment: Don't error out on reading an empty source file.
+
 
 Release 0.1.61798 (Mar 23, 2008)
 ================================
diff --git a/sphinx/environment.py b/sphinx/environment.py
index 44f015fe8..34590ddc0 100644
--- a/sphinx/environment.py
+++ b/sphinx/environment.py
@@ -457,7 +457,11 @@ class BuildEnvironment:
         Process the docinfo part of the doctree as metadata.
         """
         self.metadata[docname] = md = {}
-        docinfo = doctree[0]
+        try:
+            docinfo = doctree[0]
+        except IndexError:
+            # probably an empty document
+            return
         if docinfo.__class__ is not nodes.docinfo:
             # nothing to see here
             return