diff --git a/rigs/dummy/rot_dummy.c b/rigs/dummy/rot_dummy.c
index 05f42a12b..a538a5794 100644
--- a/rigs/dummy/rot_dummy.c
+++ b/rigs/dummy/rot_dummy.c
@@ -353,7 +353,7 @@ static void dummy_rot_simulate_rotation(ROT *rot)
  */
 static int dummy_rot_get_position(ROT *rot, azimuth_t *az, elevation_t *el)
 {
-    struct dummy_rot_priv_data *priv = (struct dummy_rot_priv_data *)
+    const struct dummy_rot_priv_data *priv = (struct dummy_rot_priv_data *)
                                        rot->state.priv;
 
     rig_debug(RIG_DEBUG_VERBOSE, "%s called\n", __func__);
@@ -415,7 +415,7 @@ static int dummy_rot_reset(ROT *rot, rot_reset_t reset)
 
 static int dummy_rot_move(ROT *rot, int direction, int speed)
 {
-    struct dummy_rot_priv_data *priv = (struct dummy_rot_priv_data *)
+    const struct dummy_rot_priv_data *priv = (struct dummy_rot_priv_data *)
                                        rot->state.priv;
 
     rig_debug(RIG_DEBUG_VERBOSE, "%s called\n", __func__);
@@ -473,7 +473,7 @@ static int dummy_set_func(ROT *rot, setting_t func, int status)
 
 static int dummy_get_func(ROT *rot, setting_t func, int *status)
 {
-    struct dummy_rot_priv_data *priv = (struct dummy_rot_priv_data *)
+    const struct dummy_rot_priv_data *priv = (struct dummy_rot_priv_data *)
                                        rot->state.priv;
 
     *status = (priv->funcs & func) ? 1 : 0;
@@ -903,7 +903,7 @@ static int dummy_get_ext_parm(ROT *rot, token_t token, value_t *val)
 
 static int dummy_rot_get_status(ROT *rot, rot_status_t *status)
 {
-    struct dummy_rot_priv_data *priv = (struct dummy_rot_priv_data *)
+    const struct dummy_rot_priv_data *priv = (struct dummy_rot_priv_data *)
                                        rot->state.priv;
 
     if (simulating)