diff --git a/configure.ac b/configure.ac
index 647325d..1551c13 100644
--- a/configure.ac
+++ b/configure.ac
@@ -175,9 +175,12 @@ AC_DEFINE_UNQUOTED(DATA_DIR, "$dir", [datadir])
 m4_pattern_allow(PKG_DATA_DIR)
 AC_DEFINE_UNQUOTED([PKG_DATA_DIR], "$dir/$PACKAGE", [pkgdatadir])
 m4_pattern_allow(PKG_DOC_DIR)
-AC_DEFINE_UNQUOTED([PKG_DOC_DIR], "$dir/doc/$PACKAGE",
+
+expanded_docdir=`eval echo ${docdir}`
+TH_EXPAND_VARS(expanded_docdir)
+AC_DEFINE_UNQUOTED([PKG_DOC_DIR], "$expanded_docdir",
            [Where package's documentation is installed])
-AC_SUBST(pkgdocdir, ["$dir/doc/$PACKAGE"])
+AC_SUBST(pkgdocdir, ["$expanded_docdir"])
 m4_pattern_allow(ICON_DIR)
 pkgicondir="$dir/icons/hicolor/scalable/apps"
 AC_DEFINE_UNQUOTED([ICON_DIR], "$pkgicondir", [Icon dir])