diff --git a/Makefile b/Makefile
index 0636d73..86ea485 100644
--- a/Makefile
+++ b/Makefile
@@ -52,6 +52,7 @@ install: check-dependencies
 	install -m 644 lib/resty/auto-ssl/utils/shell_execute.lua $(INST_LUADIR)/resty/auto-ssl/utils/shell_execute.lua
 	install -m 644 lib/resty/auto-ssl/utils/shuffle_table.lua $(INST_LUADIR)/resty/auto-ssl/utils/shuffle_table.lua
 	install -m 644 lib/resty/auto-ssl/utils/start_sockproc.lua $(INST_LUADIR)/resty/auto-ssl/utils/start_sockproc.lua
+    install -m 644 lib/resty/auto-ssl/utils/has_certificate.lua $(INST_LUADIR)/resty/auto-ssl/utils/has_certificate.lua
 	install -d $(INST_LUADIR)/resty/auto-ssl/vendor
 	install -m 644 lib/resty/auto-ssl/vendor/shell.lua $(INST_LUADIR)/resty/auto-ssl/vendor/shell.lua
 	install -d $(INST_BINDIR)/resty-auto-ssl