diff --git a/gst/gstutils.h b/gst/gstutils.h
index 89dba5d..6bef3fb 100644
--- a/gst/gstutils.h
+++ b/gst/gstutils.h
@@ -798,11 +798,11 @@ GST_READ_DOUBLE_BE(const guint8 *data)
  *
  */
 #ifdef _FOOL_GTK_DOC_
-G_INLINE_FUNC void GST_WRITE_FLOAT_LE (guint8 *data, gfloat num);
+G_INLINE_FUNC void GST_WRITE_FLOAT_LE (const guint8 *data, gfloat num);
 #endif
 
 inline static void
-GST_WRITE_FLOAT_LE(guint8 *data, gfloat num)
+GST_WRITE_FLOAT_LE(const guint8 *data, gfloat num)
 {
   union
   {
@@ -825,11 +825,11 @@ GST_WRITE_FLOAT_LE(guint8 *data, gfloat num)
  *
  */
 #ifdef _FOOL_GTK_DOC_
-G_INLINE_FUNC void GST_WRITE_FLOAT_BE (guint8 *data, gfloat num);
+G_INLINE_FUNC void GST_WRITE_FLOAT_BE (const guint8 *data, gfloat num);
 #endif
 
 inline static void
-GST_WRITE_FLOAT_BE(guint8 *data, gfloat num)
+GST_WRITE_FLOAT_BE(const guint8 *data, gfloat num)
 {
   union
   {
@@ -852,11 +852,11 @@ GST_WRITE_FLOAT_BE(guint8 *data, gfloat num)
  *
  */
 #ifdef _FOOL_GTK_DOC_
-G_INLINE_FUNC void GST_WRITE_DOUBLE_LE (guint8 *data, gdouble num);
+G_INLINE_FUNC void GST_WRITE_DOUBLE_LE (const guint8 *data, gdouble num);
 #endif
 
 inline static void
-GST_WRITE_DOUBLE_LE(guint8 *data, gdouble num)
+GST_WRITE_DOUBLE_LE(const guint8 *data, gdouble num)
 {
   union
   {
@@ -879,11 +879,11 @@ GST_WRITE_DOUBLE_LE(guint8 *data, gdouble num)
  *
  */
 #ifdef _FOOL_GTK_DOC_
-G_INLINE_FUNC void GST_WRITE_DOUBLE_BE (guint8 *data, gdouble num);
+G_INLINE_FUNC void GST_WRITE_DOUBLE_BE (const guint8 *data, gdouble num);
 #endif
 
 inline static void
-GST_WRITE_DOUBLE_BE(guint8 *data, gdouble num)
+GST_WRITE_DOUBLE_BE(const guint8 *data, gdouble num)
 {
   union
   {
diff --git a/libs/gst/base/gstbytewriter.c b/libs/gst/base/gstbytewriter.c
index 7b5d3fa..979b947 100644
--- a/libs/gst/base/gstbytewriter.c
+++ b/libs/gst/base/gstbytewriter.c
@@ -442,7 +442,7 @@ gst_byte_writer_put_##name (GstByteWriter *writer, type val) \
   if (G_UNLIKELY (!gst_byte_writer_ensure_free_space(writer, bits/8))) \
     return FALSE; \
   \
-  write_func ((guint8 *) &writer->parent.data[writer->parent.byte], val); \
+  write_func ((const guint8 *) &writer->parent.data[writer->parent.byte], val); \
   writer->parent.byte += bits/8; \
   writer->parent.size = MAX (writer->parent.size, writer->parent.byte); \
   \
