diff --git a/src/lib/Makefile.am b/src/lib/Makefile.am
index 068c3a6..dd4f6cf 100644
--- a/src/lib/Makefile.am
+++ b/src/lib/Makefile.am
@@ -1,6 +1,6 @@
 # -*- Makefile -*-
 
-AM_CFLAGS  = -Wall -I${top_srcdir}/include -D_GNU_SOURCE -DPKGLIBDIR=\"$(pkglibdir)\" -DSYSCONFDIR=\"$(sysconfdir)\" -rdynamic
+AM_CPPFLAGS  = -Wall -I${top_srcdir}/include -D_GNU_SOURCE -DPKGLIBDIR=\"$(pkglibdir)\" -DSYSCONFDIR=\"$(sysconfdir)\" -rdynamic
 AM_LDFLAGS = -L${top_builddir}/lib -ldl
 
 #nobase_pkglib_LTLIBRARIES = cls/basic.la cls/ematch/cmp.la