diff --git a/plug-ins/file-ico/ico-dialog.c b/plug-ins/file-ico/ico-dialog.c
index 8038d0ff6b..1667dc6af7 100644
--- a/plug-ins/file-ico/ico-dialog.c
+++ b/plug-ins/file-ico/ico-dialog.c
@@ -258,6 +258,7 @@ ico_dialog_update_icon_preview (GtkWidget *dialog,
     case GIMP_INDEXED_IMAGE:
     case GIMP_INDEXEDA_IMAGE:
       format = gimp_drawable_get_format (layer);
+      break;
 
     default:
       g_return_if_reached ();
diff --git a/plug-ins/file-ico/ico-save.c b/plug-ins/file-ico/ico-save.c
index d599788eb4..6d19e166a7 100644
--- a/plug-ins/file-ico/ico-save.c
+++ b/plug-ins/file-ico/ico-save.c
@@ -464,6 +464,10 @@ ico_get_layer_num_colors (gint32    layer,
     case GIMP_INDEXED_IMAGE:
     case GIMP_INDEXEDA_IMAGE:
       format = gegl_buffer_get_format (buffer);
+      /* It is possible to count the colors of indexed image more easily
+       * with gimp_image_get_colormap(), but counting only the colors
+       * actually used will allow more efficient bpp if possible. */
+      break;
 
     default:
       g_return_val_if_reached (0);
@@ -599,6 +603,7 @@ ico_image_get_reduced_buf (guint32   layer,
     case GIMP_INDEXED_IMAGE:
     case GIMP_INDEXEDA_IMAGE:
       format = gegl_buffer_get_format (buffer);
+      break;
 
     default:
       g_return_if_reached ();