diff --git a/suricata/acme_refresh/Makefile b/suricata/acme_refresh/Makefile
index 89efd2a..82b1d9f 100644
--- a/suricata/acme_refresh/Makefile
+++ b/suricata/acme_refresh/Makefile
@@ -15,8 +15,8 @@ all: $(VAULT_CERT) $(VAULT_KEY)
 
 $(VAULT_CERT): $(CERT)
 	mkdir -p $(@D)
-	install $@ $<
+	install -m 600 $^ $@
 
 $(VAULT_KEY): $(KEY)
 	mkdir -p $(@D)
-	install $@ $<
+	install -m 600 $^ $@