Update missing changes for 3.0.9r4.
diff --git a/Makefile.am b/Makefile.am
index 4b12f1f..9ecb29b 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -80,6 +80,8 @@
 
 MAKEOVERRIDES=
 
+ACLOCAL_AMFLAGS=$(ACLOCAL_AMFLAGS) -I m4
+
 lib_LTLIBRARIES = libffi.la
 noinst_LTLIBRARIES = libffi_convenience.la