diff --git a/gtk/css/gtkcssenumtypes.c.template b/gtk/css/gtkcssenumtypes.c.template
index 063b8d0..cb4c9ac 100644
--- a/gtk/css/gtkcssenumtypes.c.template
+++ b/gtk/css/gtkcssenumtypes.c.template
@@ -13,7 +13,7 @@
 GType
 @enum_name@_get_type (void)
 {
-  static volatile gsize g_define_type_id__volatile = 0;
+  static gsize g_define_type_id__volatile = 0;
 
   if (g_once_init_enter (&g_define_type_id__volatile))
     {
diff --git a/gtk/gtktextchild.c b/gtk/gtktextchild.c
index 4d5e30e..915b991 100644
--- a/gtk/gtktextchild.c
+++ b/gtk/gtktextchild.c
@@ -169,6 +169,12 @@ const GtkTextLineSegmentClass gtk_text_paintable_type = {
 GtkTextLineSegment *
 _gtk_paintable_segment_new (GdkPaintable *paintable)
 {
+  /* gcc-11 issues a diagnostic here because the size allocated
+     for SEG does not cover the entire size of a GtkTextLineSegment
+     and gcc has no way to know that the union will only be used
+     for limited types and the additional space is not needed.  */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Warray-bounds"
   GtkTextLineSegment *seg;
   guint flags;
 
@@ -204,6 +210,7 @@ _gtk_paintable_segment_new (GdkPaintable *paintable)
   g_object_ref (paintable);
 
   return seg;
+#pragma GCC diagnostic pop
 }
 
 
@@ -280,6 +287,12 @@ const GtkTextLineSegmentClass gtk_text_child_type = {
 GtkTextLineSegment *
 _gtk_widget_segment_new (GtkTextChildAnchor *anchor)
 {
+  /* gcc-11 issues a diagnostic here because the size allocated
+     for SEG does not cover the entire size of a GtkTextLineSegment
+     and gcc has no way to know that the union will only be used
+     for limited types and the additional space is not needed.  */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Warray-bounds"
   GtkTextLineSegment *seg;
 
   seg = g_slice_alloc (WIDGET_SEG_SIZE);
@@ -303,6 +316,7 @@ _gtk_widget_segment_new (GtkTextChildAnchor *anchor)
   g_object_ref (anchor);
   
   return seg;
+#pragma GCC diagnostic pop
 }
 
 void
diff --git a/gtk/gtktextsegment.c b/gtk/gtktextsegment.c
index a202ab6..aaac291 100644
--- a/gtk/gtktextsegment.c
+++ b/gtk/gtktextsegment.c
@@ -425,6 +425,13 @@ char_segment_check_func (GtkTextLineSegment *segPtr, GtkTextLine *line)
 GtkTextLineSegment*
 _gtk_toggle_segment_new (GtkTextTagInfo *info, gboolean on)
 {
+  /* gcc-11 issues a diagnostic here because the size allocated
+     for SEG does not cover the entire size of a GtkTextLineSegment
+     and gcc has no way to know that the union will only be used
+     for limited types and the additional space is not needed.  */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Warray-bounds"
+
   GtkTextLineSegment *seg;
 
   seg = g_slice_alloc (TSEG_SIZE);
@@ -440,6 +447,7 @@ _gtk_toggle_segment_new (GtkTextTagInfo *info, gboolean on)
   seg->body.toggle.inNodeCounts = 0;
 
   return seg;
+#pragma GCC diagnostic pop
 }
 
 void