diff --git a/openwrt/package/openntpd/Makefile b/openwrt/package/openntpd/Makefile
index 80c3af1b9..ed19c18d1 100644
--- a/openwrt/package/openntpd/Makefile
+++ b/openwrt/package/openntpd/Makefile
@@ -52,7 +52,9 @@ $(PKG_BUILD_DIR)/.configured:
 	touch $@
 
 $(PKG_BUILD_DIR)/.built:
-	$(MAKE) -C $(PKG_BUILD_DIR)
+	$(MAKE) -C $(PKG_BUILD_DIR) \
+		$(TARGET_CONFIGURE_OPTS) \
+		CFLAGS="$(TARGET_CFLAGS) -DUSE_ADJTIMEX"
 	touch $@
 
 $(IPKG_OPENNTPD):