diff --git a/src/core/core.c b/src/core/core.c
index d827ae69c..7fee2fc78 100644
--- a/src/core/core.c
+++ b/src/core/core.c
@@ -117,69 +117,8 @@ meta_core_get (Display *xdisplay,
         *((MetaFrameFlags*)answer) = meta_frame_get_flags (window->frame);
         break; 
       case META_CORE_GET_FRAME_TYPE:
-          {
-          MetaFrameType base_type = META_FRAME_TYPE_LAST;
-
-          switch (window->type)
-            {
-            case META_WINDOW_NORMAL:
-              base_type = META_FRAME_TYPE_NORMAL;
-              break;
-
-            case META_WINDOW_DIALOG:
-              base_type = META_FRAME_TYPE_DIALOG;
-              break;
-
-            case META_WINDOW_MODAL_DIALOG:
-              if (meta_prefs_get_attach_modal_dialogs () &&
-                  meta_window_get_transient_for (window) != NULL)
-                base_type = META_FRAME_TYPE_ATTACHED;
-              else
-                base_type = META_FRAME_TYPE_MODAL_DIALOG;
-              break;
-
-            case META_WINDOW_MENU:
-              base_type = META_FRAME_TYPE_MENU;
-              break;
-
-            case META_WINDOW_UTILITY:
-              base_type = META_FRAME_TYPE_UTILITY;
-              break;
-
-            case META_WINDOW_DESKTOP:
-            case META_WINDOW_DOCK:
-            case META_WINDOW_TOOLBAR:
-            case META_WINDOW_SPLASHSCREEN:
-	    case META_WINDOW_DROPDOWN_MENU:
-	    case META_WINDOW_POPUP_MENU:
-	    case META_WINDOW_TOOLTIP:
-	    case META_WINDOW_NOTIFICATION:
-	    case META_WINDOW_COMBO:
-	    case META_WINDOW_DND:
-	    case META_WINDOW_OVERRIDE_OTHER:
-              /* No frame */
-              base_type = META_FRAME_TYPE_LAST;
-              break;
-
-            }
-
-          if (base_type == META_FRAME_TYPE_LAST)
-            {
-              /* can't add border if undecorated */
-              *((MetaFrameType*)answer) = META_FRAME_TYPE_LAST; 
-            }
-          else if (window->border_only && base_type != META_FRAME_TYPE_ATTACHED)
-            {
-              /* override base frame type */
-              *((MetaFrameType*)answer) = META_FRAME_TYPE_BORDER; 
-            }
-          else
-            {
-              *((MetaFrameType*)answer) = base_type;
-            }
-
-          break; 
-          }
+        *((MetaFrameType*)answer) = meta_window_get_frame_type (window);
+        break;
       case META_CORE_GET_MINI_ICON:
         *((GdkPixbuf**)answer) = window->mini_icon;
         break;
diff --git a/src/core/window.c b/src/core/window.c
index 30bdeda21..226f048f9 100644
--- a/src/core/window.c
+++ b/src/core/window.c
@@ -9668,3 +9668,74 @@ meta_window_get_mutter_hints (MetaWindow *window)
 
   return window->mutter_hints;
 }
+
+/**
+ * meta_window_get_frame_type:
+ * @window: a #MetaWindow
+ *
+ * Gets the type of window decorations that should be used for this window.
+ *
+ * Return value: the frame type
+ */
+MetaFrameType
+meta_window_get_frame_type (MetaWindow *window)
+{
+  MetaFrameType base_type = META_FRAME_TYPE_LAST;
+
+  switch (window->type)
+    {
+    case META_WINDOW_NORMAL:
+      base_type = META_FRAME_TYPE_NORMAL;
+      break;
+
+    case META_WINDOW_DIALOG:
+      base_type = META_FRAME_TYPE_DIALOG;
+      break;
+
+    case META_WINDOW_MODAL_DIALOG:
+      if (meta_prefs_get_attach_modal_dialogs () &&
+          meta_window_get_transient_for (window) != NULL)
+        base_type = META_FRAME_TYPE_ATTACHED;
+      else
+        base_type = META_FRAME_TYPE_MODAL_DIALOG;
+      break;
+
+    case META_WINDOW_MENU:
+      base_type = META_FRAME_TYPE_MENU;
+      break;
+
+    case META_WINDOW_UTILITY:
+      base_type = META_FRAME_TYPE_UTILITY;
+      break;
+
+    case META_WINDOW_DESKTOP:
+    case META_WINDOW_DOCK:
+    case META_WINDOW_TOOLBAR:
+    case META_WINDOW_SPLASHSCREEN:
+    case META_WINDOW_DROPDOWN_MENU:
+    case META_WINDOW_POPUP_MENU:
+    case META_WINDOW_TOOLTIP:
+    case META_WINDOW_NOTIFICATION:
+    case META_WINDOW_COMBO:
+    case META_WINDOW_DND:
+    case META_WINDOW_OVERRIDE_OTHER:
+      /* No frame */
+      base_type = META_FRAME_TYPE_LAST;
+      break;
+    }
+
+  if (base_type == META_FRAME_TYPE_LAST)
+    {
+      /* can't add border if undecorated */
+      return META_FRAME_TYPE_LAST;
+    }
+  else if (window->border_only && base_type != META_FRAME_TYPE_ATTACHED)
+    {
+      /* override base frame type */
+      return META_FRAME_TYPE_BORDER;
+    }
+  else
+    {
+      return base_type;
+    }
+}
diff --git a/src/include/window.h b/src/include/window.h
index b3d3c4cf3..db32ac4d6 100644
--- a/src/include/window.h
+++ b/src/include/window.h
@@ -144,4 +144,7 @@ const char *meta_window_get_client_machine (MetaWindow *window);
 gboolean    meta_window_is_remote (MetaWindow *window);
 gboolean    meta_window_is_modal (MetaWindow *window);
 const char *meta_window_get_mutter_hints (MetaWindow *window);
+
+MetaFrameType meta_window_get_frame_type (MetaWindow *window);
+
 #endif