diff --git a/src/gui_gtk_x11.c b/src/gui_gtk_x11.c
index 3ee2957..359bf64 100644
--- a/src/gui_gtk_x11.c
+++ b/src/gui_gtk_x11.c
@@ -3346,6 +3346,8 @@
 	case TBIS_SMALL:    size = GTK_ICON_SIZE_SMALL_TOOLBAR;	break;
 	case TBIS_MEDIUM:   size = GTK_ICON_SIZE_BUTTON;	break;
 	case TBIS_LARGE:    size = GTK_ICON_SIZE_LARGE_TOOLBAR;	break;
+	case TBIS_HUGE:     size = GTK_ICON_SIZE_DND;		break;
+	case TBIS_GIANT:    size = GTK_ICON_SIZE_DIALOG;	break;
 	default:	    size = GTK_ICON_SIZE_INVALID;	break;
     }
     oldsize = gtk_toolbar_get_icon_size(toolbar);
diff --git a/src/option.h b/src/option.h
index 2f1f04f..6b194bc 100644
--- a/src/option.h
+++ b/src/option.h
@@ -871,12 +871,14 @@
 EXTERN char_u	*p_tbis;	/* 'toolbariconsize' */
 EXTERN unsigned tbis_flags;
 # ifdef IN_OPTION_C
-static char *(p_tbis_values[]) = {"tiny", "small", "medium", "large", NULL};
+static char *(p_tbis_values[]) = {"tiny", "small", "medium", "large", "huge", "giant", NULL};
 # endif
 # define TBIS_TINY		0x01
 # define TBIS_SMALL		0x02
 # define TBIS_MEDIUM		0x04
 # define TBIS_LARGE		0x08
+# define TBIS_HUGE		0x10
+# define TBIS_GIANT		0x20
 #endif
 EXTERN long	p_ttyscroll;	/* 'ttyscroll' */
 #if defined(FEAT_MOUSE) && (defined(UNIX) || defined(VMS))
diff --git a/src/version.c b/src/version.c
index a760c76..f27cd55 100644
--- a/src/version.c
+++ b/src/version.c
@@ -744,6 +744,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1525,
+/**/
     1524,
 /**/
     1523,