diff --git a/libs/gst/controller/gstinterpolationcontrolsource.c b/libs/gst/controller/gstinterpolationcontrolsource.c
index 5730fdff27..397ae4f9c6 100644
--- a/libs/gst/controller/gstinterpolationcontrolsource.c
+++ b/libs/gst/controller/gstinterpolationcontrolsource.c
@@ -421,7 +421,7 @@ gst_control_point_find (gconstpointer p1, gconstpointer p2)
 
 static GstControlPoint *
 _make_new_cp (GstInterpolationControlSource * self, GstClockTime timestamp,
-    GValue * value)
+    const GValue * value)
 {
   GstControlPoint *cp;
 
@@ -436,7 +436,7 @@ _make_new_cp (GstInterpolationControlSource * self, GstClockTime timestamp,
 
 static void
 gst_interpolation_control_source_set_internal (GstInterpolationControlSource *
-    self, GstClockTime timestamp, GValue * value)
+    self, GstClockTime timestamp, const GValue * value)
 {
   GSequenceIter *iter;
 
@@ -486,7 +486,7 @@ done:
  */
 gboolean
 gst_interpolation_control_source_set (GstInterpolationControlSource * self,
-    GstClockTime timestamp, GValue * value)
+    GstClockTime timestamp, const GValue * value)
 {
   g_return_val_if_fail (GST_IS_INTERPOLATION_CONTROL_SOURCE (self), FALSE);
   g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), FALSE);
@@ -511,9 +511,9 @@ gst_interpolation_control_source_set (GstInterpolationControlSource * self,
  */
 gboolean
 gst_interpolation_control_source_set_from_list (GstInterpolationControlSource *
-    self, GSList * timedvalues)
+    self, const GSList * timedvalues)
 {
-  GSList *node;
+  const GSList *node;
   GstTimedValue *tv;
   gboolean res = FALSE;
 
diff --git a/libs/gst/controller/gstinterpolationcontrolsource.h b/libs/gst/controller/gstinterpolationcontrolsource.h
index 42d2e76fcd..bac004101c 100644
--- a/libs/gst/controller/gstinterpolationcontrolsource.h
+++ b/libs/gst/controller/gstinterpolationcontrolsource.h
@@ -97,8 +97,8 @@ GType gst_interpolation_control_source_get_type (void);
 
 GstInterpolationControlSource *gst_interpolation_control_source_new (void);
 gboolean gst_interpolation_control_source_set_interpolation_mode (GstInterpolationControlSource *self, GstInterpolateMode mode);
-gboolean gst_interpolation_control_source_set (GstInterpolationControlSource * self, GstClockTime timestamp, GValue * value);
-gboolean gst_interpolation_control_source_set_from_list (GstInterpolationControlSource * self, GSList * timedvalues);
+gboolean gst_interpolation_control_source_set (GstInterpolationControlSource * self, GstClockTime timestamp, const GValue * value);
+gboolean gst_interpolation_control_source_set_from_list (GstInterpolationControlSource * self, const GSList * timedvalues);
 gboolean gst_interpolation_control_source_unset (GstInterpolationControlSource * self, GstClockTime timestamp);
 void gst_interpolation_control_source_unset_all (GstInterpolationControlSource *self);
 GList *gst_interpolation_control_source_get_all (GstInterpolationControlSource * self);