diff --git a/docs/reference/gtk/gtk4-image-tool.rst b/docs/reference/gtk/gtk4-image-tool.rst
index 911ab9d9c8..3c9b686888 100644
--- a/docs/reference/gtk/gtk4-image-tool.rst
+++ b/docs/reference/gtk/gtk4-image-tool.rst
@@ -41,6 +41,11 @@ Showing
 
 The ``show`` command displays one or more images, side-by-side.
 
+``--undecorated``
+
+Removes window decorations. This is meant for rendering of exactly the image
+without any titlebar.
+
 Compare
 ^^^^^^^
 
diff --git a/tools/gtk-image-tool-show.c b/tools/gtk-image-tool-show.c
index 9bc3c75343..3b85292fa5 100644
--- a/tools/gtk-image-tool-show.c
+++ b/tools/gtk-image-tool-show.c
@@ -41,7 +41,8 @@ quit_cb (GtkWidget *widget,
 }
 
 static void
-show_files (char **filenames)
+show_files (char     **filenames,
+            gboolean   decorated)
 {
   GtkWidget *sw;
   GtkWidget *window;
@@ -64,6 +65,9 @@ show_files (char **filenames)
       g_free (name);
     }
 
+  gtk_window_set_decorated (GTK_WINDOW (window), decorated);
+  gtk_window_set_resizable (GTK_WINDOW (window), decorated);
+
   gtk_window_set_title (GTK_WINDOW (window), title->str);
   g_string_free (title, TRUE);
 
@@ -108,7 +112,10 @@ do_show (int          *argc,
 {
   GOptionContext *context;
   char **filenames = NULL;
+  gboolean decorated = TRUE;
   const GOptionEntry entries[] = {
+    { "undecorated", 0, G_OPTION_FLAG_REVERSE, G_OPTION_ARG_NONE, &decorated, N_("Don't add a titlebar"), NULL },
+
     { G_OPTION_REMAINING, 0, 0, G_OPTION_ARG_FILENAME_ARRAY, &filenames, NULL, N_("FILE…") },
     { NULL, }
   };
@@ -135,7 +142,7 @@ do_show (int          *argc,
       exit (1);
     }
 
-  show_files (filenames);
+  show_files (filenames, decorated);
 
   g_strfreev (filenames);
 }