diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c
index 65813b68ccd8b23b56a76b5a19f7afddc1249cdd..a12809c2d5e36a5c3b0726e7be9c27300b726d5e 100644
--- a/src/libvirt-domain.c
+++ b/src/libvirt-domain.c
@@ -12576,6 +12576,8 @@ virDomainAgentSetResponseTimeout(virDomainPtr domain,
     virCheckDomainReturn(domain, -1);
     conn = domain->conn;
 
+    virCheckReadOnlyGoto(conn->flags, error);
+
     if (conn->driver->domainAgentSetResponseTimeout) {
         if (conn->driver->domainAgentSetResponseTimeout(domain, timeout, flags) < 0)
             goto error;