diff --git a/girs/Gst-1.0.gir b/girs/Gst-1.0.gir
index 22cc9724ef..9f8caf76cb 100644
--- a/girs/Gst-1.0.gir
+++ b/girs/Gst-1.0.gir
@@ -24559,7 +24559,7 @@ MT safe.</doc>
             <doc xml:space="preserve" filename="../subprojects/gstreamer/gst/gstmessage.c">The GError for this message.</doc>
             <type name="GLib.Error" c:type="GError*"/>
           </parameter>
-          <parameter name="debug" transfer-ownership="none">
+          <parameter name="debug" transfer-ownership="none" nullable="1" allow-none="1">
             <doc xml:space="preserve" filename="../subprojects/gstreamer/gst/gstmessage.c">A debugging string.</doc>
             <type name="utf8" c:type="const gchar*"/>
           </parameter>
@@ -24584,7 +24584,7 @@ receiving this message should stop the pipeline.</doc>
             <doc xml:space="preserve" filename="../subprojects/gstreamer/gst/gstmessage.c">The GError for this message.</doc>
             <type name="GLib.Error" c:type="GError*"/>
           </parameter>
-          <parameter name="debug" transfer-ownership="none">
+          <parameter name="debug" transfer-ownership="none" nullable="1" allow-none="1">
             <doc xml:space="preserve" filename="../subprojects/gstreamer/gst/gstmessage.c">A debugging string.</doc>
             <type name="utf8" c:type="const gchar*"/>
           </parameter>
@@ -24633,7 +24633,7 @@ MT safe.</doc>
             <doc xml:space="preserve" filename="../subprojects/gstreamer/gst/gstmessage.c">The GError for this message.</doc>
             <type name="GLib.Error" c:type="GError*"/>
           </parameter>
-          <parameter name="debug" transfer-ownership="none">
+          <parameter name="debug" transfer-ownership="none" nullable="1" allow-none="1">
             <doc xml:space="preserve" filename="../subprojects/gstreamer/gst/gstmessage.c">A debugging string.</doc>
             <type name="utf8" c:type="const gchar*"/>
           </parameter>
@@ -24656,7 +24656,7 @@ MT safe.</doc>
             <doc xml:space="preserve" filename="../subprojects/gstreamer/gst/gstmessage.c">The GError for this message.</doc>
             <type name="GLib.Error" c:type="GError*"/>
           </parameter>
-          <parameter name="debug" transfer-ownership="none">
+          <parameter name="debug" transfer-ownership="none" nullable="1" allow-none="1">
             <doc xml:space="preserve" filename="../subprojects/gstreamer/gst/gstmessage.c">A debugging string.</doc>
             <type name="utf8" c:type="const gchar*"/>
           </parameter>
@@ -25323,7 +25323,7 @@ MT safe.</doc>
             <doc xml:space="preserve" filename="../subprojects/gstreamer/gst/gstmessage.c">The GError for this message.</doc>
             <type name="GLib.Error" c:type="GError*"/>
           </parameter>
-          <parameter name="debug" transfer-ownership="none">
+          <parameter name="debug" transfer-ownership="none" nullable="1" allow-none="1">
             <doc xml:space="preserve" filename="../subprojects/gstreamer/gst/gstmessage.c">A debugging string.</doc>
             <type name="utf8" c:type="const gchar*"/>
           </parameter>
@@ -25346,7 +25346,7 @@ MT safe.</doc>
             <doc xml:space="preserve" filename="../subprojects/gstreamer/gst/gstmessage.c">The GError for this message.</doc>
             <type name="GLib.Error" c:type="GError*"/>
           </parameter>
-          <parameter name="debug" transfer-ownership="none">
+          <parameter name="debug" transfer-ownership="none" nullable="1" allow-none="1">
             <doc xml:space="preserve" filename="../subprojects/gstreamer/gst/gstmessage.c">A debugging string.</doc>
             <type name="utf8" c:type="const gchar*"/>
           </parameter>
diff --git a/subprojects/gstreamer/gst/gstmessage.c b/subprojects/gstreamer/gst/gstmessage.c
index a82dea7b9d..cf2dc77eee 100644
--- a/subprojects/gstreamer/gst/gstmessage.c
+++ b/subprojects/gstreamer/gst/gstmessage.c
@@ -526,7 +526,7 @@ gst_message_writable_details (GstMessage * message)
  * gst_message_new_error_with_details:
  * @src: (transfer none) (nullable): The object originating the message.
  * @error: (transfer none): The GError for this message.
- * @debug: A debugging string.
+ * @debug: (nullable): A debugging string.
  * @details: (transfer full) (nullable): A GstStructure with details
  *
  * Create a new error message. The message will copy @error and
@@ -565,7 +565,7 @@ gst_message_new_error_with_details (GstObject * src, GError * error,
  * gst_message_new_error:
  * @src: (transfer none) (nullable): The object originating the message.
  * @error: (transfer none): The GError for this message.
- * @debug: A debugging string.
+ * @debug: (nullable): A debugging string.
  *
  * Create a new error message. The message will copy @error and
  * @debug. This message is posted by element when a fatal event
@@ -629,7 +629,7 @@ gst_message_parse_error_writable_details (GstMessage * message,
  * gst_message_new_warning_with_details:
  * @src: (transfer none) (nullable): The object originating the message.
  * @error: (transfer none): The GError for this message.
- * @debug: A debugging string.
+ * @debug: (nullable): A debugging string.
  * @details: (transfer full) (nullable): A GstStructure with details
  *
  * Create a new warning message. The message will make copies of @error and
@@ -666,7 +666,7 @@ gst_message_new_warning_with_details (GstObject * src, GError * error,
  * gst_message_new_warning:
  * @src: (transfer none) (nullable): The object originating the message.
  * @error: (transfer none): The GError for this message.
- * @debug: A debugging string.
+ * @debug: (nullable): A debugging string.
  *
  * Create a new warning message. The message will make copies of @error and
  * @debug.
@@ -728,7 +728,7 @@ gst_message_parse_warning_writable_details (GstMessage * message,
  * gst_message_new_info_with_details:
  * @src: (transfer none) (nullable): The object originating the message.
  * @error: (transfer none): The GError for this message.
- * @debug: A debugging string.
+ * @debug: (nullable): A debugging string.
  * @details: (transfer full) (nullable): A GstStructure with details
  *
  * Create a new info message. The message will make copies of @error and
@@ -765,7 +765,7 @@ gst_message_new_info_with_details (GstObject * src, GError * error,
  * gst_message_new_info:
  * @src: (transfer none) (nullable): The object originating the message.
  * @error: (transfer none): The GError for this message.
- * @debug: A debugging string.
+ * @debug: (nullable): A debugging string.
  *
  * Create a new info message. The message will make copies of @error and
  * @debug.