diff --git a/src/Text/Pandoc/Shared.hs b/src/Text/Pandoc/Shared.hs
index 23b06b47f..6d00b1468 100644
--- a/src/Text/Pandoc/Shared.hs
+++ b/src/Text/Pandoc/Shared.hs
@@ -965,10 +965,13 @@ safeStrRead s = case reads s of
 -- XDG_DATA_HOME (or its default value), but for backwards compatibility,
 -- we fall back to the legacy user data directory ($HOME/.pandoc on *nix)
 -- if the XDG_DATA_HOME is missing and this exists.  If neither directory
--- is present, we return the XDG data directory.
+-- is present, we return the XDG data directory.  If the XDG data directory
+-- is not defined (e.g. because we are in an environment where $HOME is
+-- not defined), we return the empty string.
 defaultUserDataDir :: IO FilePath
 defaultUserDataDir = do
-  xdgDir <- getXdgDirectory XdgData "pandoc"
+  xdgDir <- E.catch (getXdgDirectory XdgData "pandoc")
+               (\(_ :: E.SomeException) -> return mempty)
   legacyDir <- getAppUserDataDirectory "pandoc"
   xdgExists <- doesDirectoryExist xdgDir
   legacyDirExists <- doesDirectoryExist legacyDir