diff --git a/sample/Makefile.am b/sample/Makefile.am
index b749b806..d4a113ce 100644
--- a/sample/Makefile.am
+++ b/sample/Makefile.am
@@ -1,8 +1,7 @@
 AUTOMAKE_OPTIONS = foreign no-dependencies
 
 LDADD = ../libevent.la
-CPPFPLAGS = -I.. 
-CFLAGS = -I../compat
+AM_CFLAGS = -I../compat
 
 noinst_PROGRAMS = event-test time-test signal-test