diff --git a/openbsc/src/osmo-nitb/Makefile.am b/openbsc/src/osmo-nitb/Makefile.am
index 2a6d2fc..b91490b 100644
--- a/openbsc/src/osmo-nitb/Makefile.am
+++ b/openbsc/src/osmo-nitb/Makefile.am
@@ -13,6 +13,7 @@
 	$(LIBOSMOCTRL_CFLAGS) \
 	$(LIBOSMOABIS_CFLAGS) \
 	$(LIBSMPP34_CFLAGS) \
+	$(LIBCRYPTO_CFLAGS) \
 	$(NULL)
 
 AM_LDFLAGS = \