Add Include to the list of source directories.
diff --git a/configure.in b/configure.in
index 02fe99e..c9756f1 100644
--- a/configure.in
+++ b/configure.in
@@ -1413,7 +1413,7 @@
 #fi
 
 AC_SUBST(SRCDIRS)
-SRCDIRS="Parser Grammar Objects Python Modules"
+SRCDIRS="Include Parser Grammar Objects Python Modules"
 AC_MSG_CHECKING(for build directories)
 for dir in $SRCDIRS; do
     if test ! -d $dir; then