diff --git a/src/mhd2/daemon_set_options.c b/src/mhd2/daemon_set_options.c
index 356db9e7..f0641656 100644
--- a/src/mhd2/daemon_set_options.c
+++ b/src/mhd2/daemon_set_options.c
@@ -24,6 +24,9 @@ MHD_daemon_set_options (struct MHD_Daemon *daemon,
 {
   size_t i;
 
+  if (mhd_DAEMON_STATE_NOT_STARTED != daemon->state)
+    return MHD_SC_TOO_LATE;
+
   for (i=0;i<options_max_num;i++)
   {
     const struct MHD_DaemonOptionAndValue *const option = options + i;
diff --git a/src/mhd2/response_set_options.c b/src/mhd2/response_set_options.c
index 89ad9e28..5895d981 100644
--- a/src/mhd2/response_set_options.c
+++ b/src/mhd2/response_set_options.c
@@ -23,6 +23,9 @@ MHD_response_set_options (struct MHD_Response *response,
 {
   size_t i;
 
+  if (response->frozen)
+    return MHD_SC_TOO_LATE;
+
   for (i=0;i<options_max_num;i++)
   {
     const struct MHD_ResponseOptionAndValue *const option = options + i;