diff --git a/libgimpwidgets/gimpbrowser.c b/libgimpwidgets/gimpbrowser.c
index 81b39ef9f7..b5de24d5cd 100644
--- a/libgimpwidgets/gimpbrowser.c
+++ b/libgimpwidgets/gimpbrowser.c
@@ -293,7 +293,7 @@ gimp_browser_add_search_types (GimpBrowser *browser,
  * gimp_browser_get_left_vbox:
  * @browser: a #GimpBrowser widget
  *
- * Returns: The left vbox.
+ * Returns: (transfer none): The left vbox.
  *
  * Since: 3.0
  **/
@@ -313,7 +313,7 @@ gimp_browser_get_left_vbox (GimpBrowser *browser)
  * gimp_browser_get_right_vbox:
  * @browser: a #GimpBrowser widget
  *
- * Returns: The right vbox.
+ * Returns: (transfer none): The right vbox.
  *
  * Since: 3.0
  **/
diff --git a/libgimpwidgets/gimpchainbutton.c b/libgimpwidgets/gimpchainbutton.c
index 631b42a584..680a16626d 100644
--- a/libgimpwidgets/gimpchainbutton.c
+++ b/libgimpwidgets/gimpchainbutton.c
@@ -425,7 +425,7 @@ gimp_chain_button_get_active (GimpChainButton *button)
  * gimp_chain_button_get_button
  * @button: A #GimpChainButton.
  *
- * Returns: The #GimpChainButton's button.
+ * Returns: (transfer none): The #GimpChainButton's button.
  *
  * Since: 3.0
  */
diff --git a/libgimpwidgets/gimpcolorbutton.c b/libgimpwidgets/gimpcolorbutton.c
index 6657f8777c..966fe9cc30 100644
--- a/libgimpwidgets/gimpcolorbutton.c
+++ b/libgimpwidgets/gimpcolorbutton.c
@@ -888,7 +888,7 @@ gimp_color_button_set_color_config (GimpColorButton *button,
  * gimp_color_button_get_ui_manager:
  * @button: a #GimpColorButton.
  *
- * Returns: The @button's #GtkUIManager.
+ * Returns: (transfer none): The @button's #GtkUIManager.
  *
  * Since: 2.10
  **/
diff --git a/libgimpwidgets/gimpcolordisplay.c b/libgimpwidgets/gimpcolordisplay.c
index c00d29d1fa..ed01a567f6 100644
--- a/libgimpwidgets/gimpcolordisplay.c
+++ b/libgimpwidgets/gimpcolordisplay.c
@@ -414,7 +414,7 @@ gimp_color_display_get_enabled (GimpColorDisplay *display)
  * gimp_color_display_get_config:
  * @display:
  *
- * Return value: a pointer to the #GimpColorConfig object or %NULL.
+ * Return value: (transfer none): a pointer to the #GimpColorConfig object or %NULL.
  *
  * Since: 2.4
  **/
@@ -430,7 +430,7 @@ gimp_color_display_get_config (GimpColorDisplay *display)
  * gimp_color_display_get_managed:
  * @display:
  *
- * Return value: a pointer to the #GimpColorManaged object or %NULL.
+ * Return value: (transfer none): a pointer to the #GimpColorManaged object or %NULL.
  *
  * Since: 2.4
  **/
diff --git a/libgimpwidgets/gimpcolornotebook.c b/libgimpwidgets/gimpcolornotebook.c
index 534ed91f93..6cfe3c7eec 100644
--- a/libgimpwidgets/gimpcolornotebook.c
+++ b/libgimpwidgets/gimpcolornotebook.c
@@ -510,8 +510,8 @@ gimp_color_notebook_remove_selector (GtkContainer      *container,
  * This function adds and removed pages to / from a #GimpColorNotebook.
  * The @page_type passed must be a #GimpColorSelector subtype.
  *
- * Return value: The new page widget, if @has_page was #TRUE, or #NULL
- *               if @has_page was #FALSE.
+ * Return value: (transfer none): The new page widget, if @has_page was
+ *               #TRUE, or #NULL if @has_page was #FALSE.
  **/
 GtkWidget *
 gimp_color_notebook_set_has_page (GimpColorNotebook *notebook,
@@ -552,7 +552,7 @@ gimp_color_notebook_set_has_page (GimpColorNotebook *notebook,
  * gimp_color_notebook_get_notebook:
  * @notebook:  A #GimpColorNotebook widget.
  *
- * Return value: The #GtkNotebook inside.
+ * Return value: (transfer none): The #GtkNotebook inside.
  *
  * Since: 3.0
  **/
@@ -568,7 +568,7 @@ gimp_color_notebook_get_notebook (GimpColorNotebook *notebook)
  * gimp_color_notebook_get_selectors:
  * @notebook:  A #GimpColorNotebook widget.
  *
- * Return value: The notebook's list of #GimpColorSelector's.
+ * Return value: (transfer none): The notebook's list of #GimpColorSelector's.
  *
  * Since: 3.0
  **/
@@ -584,7 +584,7 @@ gimp_color_notebook_get_selectors (GimpColorNotebook *notebook)
  * gimp_color_notebook_get_current_selector:
  * @notebook:  A #GimpColorNotebook widget.
  *
- * Return value: The active page's #GimpColorSelector.
+ * Return value: (transfer none): The active page's #GimpColorSelector.
  *
  * Since: 3.0
  **/
diff --git a/libgimpwidgets/gimpcolorprofilecombobox.c b/libgimpwidgets/gimpcolorprofilecombobox.c
index edfe5238e8..459bf42fd8 100644
--- a/libgimpwidgets/gimpcolorprofilecombobox.c
+++ b/libgimpwidgets/gimpcolorprofilecombobox.c
@@ -446,9 +446,9 @@ gimp_color_profile_combo_box_set_active_file (GimpColorProfileComboBox *combo,
  * gimp_color_profile_combo_box_get_active_file:
  * @combo: a #GimpColorProfileComboBox
  *
- * Return value: The file of the currently selected color profile,
- *               release using g_object_unref() when it is not any
- *               longer needed.
+ * Return value: (transfer full): The file of the currently selected
+ *               color profile, release using g_object_unref() when it
+ *               is not any longer needed.
  *
  * Since: 2.10
  **/
diff --git a/libgimpwidgets/gimpcolorselection.c b/libgimpwidgets/gimpcolorselection.c
index 1a7cca95b2..bd95532ad4 100644
--- a/libgimpwidgets/gimpcolorselection.c
+++ b/libgimpwidgets/gimpcolorselection.c
@@ -595,7 +595,7 @@ gimp_color_selection_set_config (GimpColorSelection *selection,
  * gimp_color_selection_get_notebook:
  * @selection: A #GimpColorSelection widget.
  *
- * Returns: The selection's #GimpColorNotebook.
+ * Returns: (transfer none): The selection's #GimpColorNotebook.
  *
  * Since: 3.0
  */
@@ -611,7 +611,7 @@ gimp_color_selection_get_notebook (GimpColorSelection *selection)
  * gimp_color_selection_get_right_vbox:
  * @selection: A #GimpColorSelection widget.
  *
- * Returns: The selection's right #GtkBox which contains the color scales.
+ * Returns: (transfer none): The selection's right #GtkBox which contains the color scales.
  *
  * Since: 3.0
  */
diff --git a/libgimpwidgets/gimppropwidgets.c b/libgimpwidgets/gimppropwidgets.c
index 9bf9d71795..4dab4c9dca 100644
--- a/libgimpwidgets/gimppropwidgets.c
+++ b/libgimpwidgets/gimppropwidgets.c
@@ -2792,7 +2792,7 @@ static gint   gimp_prop_size_entry_num_chars   (gdouble        lower,
  * single value.  Use gimp_prop_coordinates_new() to create a size
  * entry holding two values.
  *
- * Return value:  A new #GimpSizeEntry widget.
+ * Return value: (transfer full): A new #GimpSizeEntry widget.
  *
  * Since: 2.4
  */
diff --git a/libgimpwidgets/gimpwidgets.c b/libgimpwidgets/gimpwidgets.c
index d4effbeabb..15bbcee3eb 100644
--- a/libgimpwidgets/gimpwidgets.c
+++ b/libgimpwidgets/gimpwidgets.c
@@ -53,7 +53,7 @@
  * Convenience function to create a group of radio buttons embedded into
  * a #GtkFrame or #GtkVBox.
  *
- * Returns: A #GtkFrame or #GtkVBox (depending on @in_frame).
+ * Returns: (transfer full): A #GtkFrame or #GtkVBox (depending on @in_frame).
  **/
 GtkWidget *
 gimp_radio_group_new (gboolean            in_frame,
@@ -162,7 +162,7 @@ gimp_radio_group_new (gboolean            in_frame,
  * Convenience function to create a group of radio buttons embedded into
  * a #GtkFrame or #GtkVBox.
  *
- * Returns: A #GtkFrame or #GtkVBox (depending on @in_frame).
+ * Returns: (transfer full): A #GtkFrame or #GtkVBox (depending on @in_frame).
  **/
 GtkWidget *
 gimp_radio_group_new2 (gboolean         in_frame,
@@ -269,7 +269,7 @@ gimp_radio_group_new2 (gboolean         in_frame,
  * pointers, since that is a very common case (mapping an enum to a radio
  * group).
  *
- * Returns: A #GtkFrame or #GtkVBox (depending on @in_frame).
+ * Returns: (transfer full): A #GtkFrame or #GtkVBox (depending on @in_frame).
  **/
 GtkWidget *
 gimp_int_radio_group_new (gboolean         in_frame,
@@ -435,8 +435,8 @@ gimp_random_seed_update (GtkWidget *widget,
  * Creates a widget that allows the user to control how the random number
  * generator is initialized.
  *
- * Returns: A #GtkHBox containing a #GtkSpinButton for the seed and
- *          a #GtkButton for setting a random seed.
+ * Returns: (transfer full): A #GtkHBox containing a #GtkSpinButton for
+ *          the seed and a #GtkButton for setting a random seed.
  **/
 GtkWidget *
 gimp_random_seed_new (guint    *seed,
@@ -658,7 +658,7 @@ gimp_coordinates_chainbutton_toggled (GimpChainButton *button,
  * coordinates/sizes with a #GimpChainButton attached to constrain either the
  * two fields' values or the ratio between them.
  *
- * Returns: The new #GimpSizeEntry.
+ * Returns: (transfer full): The new #GimpSizeEntry.
  **/
 GtkWidget *
 gimp_coordinates_new (GimpUnit         unit,
diff --git a/libgimpwidgets/gimpwidgetsutils.c b/libgimpwidgets/gimpwidgetsutils.c
index fb79218362..840c6c76fc 100644
--- a/libgimpwidgets/gimpwidgetsutils.c
+++ b/libgimpwidgets/gimpwidgetsutils.c
@@ -118,7 +118,7 @@ find_mnemonic_widget (GtkWidget *widget,
  * Note that the @label_text can be %NULL and that the widget will be
  * attached starting at (@column + 1) in this case, too.
  *
- * Returns: The created #GtkLabel.
+ * Returns: (transfer none): The created #GtkLabel.
  **/
 GtkWidget *
 gimp_grid_attach_aligned (GtkGrid     *grid,
@@ -474,7 +474,7 @@ monitor_number (GdkMonitor *monitor)
  *
  * Since: 3.0
  *
- * Return value: the monitor's #GimpColorProfile, or %NULL.
+ * Return value: (transfer full): the monitor's #GimpColorProfile, or %NULL.
  **/
 GimpColorProfile *
 gimp_monitor_get_color_profile (GdkMonitor *monitor)
diff --git a/libgimpwidgets/gimpzoommodel.c b/libgimpwidgets/gimpzoommodel.c
index 00360815d3..33db9e7d88 100644
--- a/libgimpwidgets/gimpzoommodel.c
+++ b/libgimpwidgets/gimpzoommodel.c
@@ -540,7 +540,7 @@ zoom_out_button_callback (GimpZoomModel *model,
  * @zoom_type:
  * @icon_size: use 0 for a button with text labels
  *
- * Return value: a newly created GtkButton
+ * Return value: (transfer full): a newly created GtkButton
  *
  * Since GIMP 2.4
  **/