diff --git a/libgimpcolor/gimpcairo.c b/libgimpcolor/gimpcairo.c
index e1e57d9bbb..2d05213c92 100644
--- a/libgimpcolor/gimpcairo.c
+++ b/libgimpcolor/gimpcairo.c
@@ -181,7 +181,7 @@ gimp_cairo_surface_get_format (cairo_surface_t *surface)
  * It must only be called on image surfaces, calling it on other surface
  * types is an error.
  *
- * Return value: a #GeglBuffer
+ * Return value: (transfer full): a #GeglBuffer
  *
  * Since: 2.10
  **/
diff --git a/libgimpcolor/gimppixbuf.c b/libgimpcolor/gimppixbuf.c
index 235b84d7f6..682c896055 100644
--- a/libgimpcolor/gimppixbuf.c
+++ b/libgimpcolor/gimppixbuf.c
@@ -72,7 +72,7 @@ gimp_pixbuf_get_format (GdkPixbuf *pixbuf)
  * be kept around for as long as the buffer exists; otherwise the
  * pixels are copied.
  *
- * Return value: a new #GeglBuffer.
+ * Return value: (transfer full): a new #GeglBuffer.
  *
  * Since: 2.10
  **/
diff --git a/libgimpcolor/gimprgb.c b/libgimpcolor/gimprgb.c
index 913b83974a..37123d6878 100644
--- a/libgimpcolor/gimprgb.c
+++ b/libgimpcolor/gimprgb.c
@@ -744,7 +744,7 @@ gimp_param_rgb_values_cmp (GParamSpec   *pspec,
  * Creates a param spec to hold an #GimpRGB value.
  * See g_param_spec_internal() for more information.
  *
- * Returns: a newly allocated #GParamSpec instance
+ * Returns: (transfer full): a newly allocated #GParamSpec instance
  *
  * Since: 2.4
  **/