diff --git a/sample/include.am b/sample/include.am
index d1a7242f..cc003b78 100644
--- a/sample/include.am
+++ b/sample/include.am
@@ -16,16 +16,16 @@ SAMPLES = \
 if OPENSSL
 SAMPLES += sample/le-proxy
 sample_le_proxy_SOURCES = sample/le-proxy.c
-sample_le_proxy_LDADD = libevent.la libevent_openssl.la ${OPENSSL_LIBS} ${OPENSSL_LIBADD}
-sample_le_proxy_INCLUDES = $(OPENSSL_INCS)
+sample_le_proxy_LDADD = libevent.la libevent_openssl.la $(OPENSSL_LIBS) $(OPENSSL_LIBADD)
+sample_le_proxy_CPPFLAGS = $(AM_CPPFLAGS) $(OPENSSL_INCS)
 
 SAMPLES += sample/https-client
 sample_https_client_SOURCES = \
 	sample/https-client.c \
 	sample/hostcheck.c \
 	sample/openssl_hostname_validation.c
-sample_https_client_LDADD = libevent.la libevent_openssl.la ${OPENSSL_LIBS} ${OPENSSL_LIBADD}
-sample_https_client_INCLUDES = $(OPENSSL_INCS)
+sample_https_client_LDADD = libevent.la libevent_openssl.la $(OPENSSL_LIBS) $(OPENSSL_LIBADD)
+sample_https_client_CPPFLAGS = $(AM_CPPFLAGS) $(OPENSSL_INCS)
 noinst_HEADERS += \
 	sample/hostcheck.h \
 	sample/openssl_hostname_validation.h