diff --git a/src/tls/cockpit-certificate-helper.in b/src/tls/cockpit-certificate-helper.in
index e109bcd51a2..86a6d3de99f 100644
--- a/src/tls/cockpit-certificate-helper.in
+++ b/src/tls/cockpit-certificate-helper.in
@@ -81,6 +81,9 @@ cmd_selfsign() {
     test ! -e "${CA_FILE}" || install_cert "${CA_FILE}"
     install_cert "${CERTFILE}"
     install_key "${KEYFILE}"
+
+    # Force writing of new files on disk.
+    sync
 }
 
 cmd_ipa_request() {