diff --git a/bin/meld b/bin/meld
index 4756305..3d65ad2 100755
--- a/bin/meld
+++ b/bin/meld
@@ -191,6 +191,9 @@ def setup_resources():
     icon_dir = os.path.join(meld.conf.DATADIR, "icons")
     Gtk.IconTheme.get_default().append_search_path(icon_dir)
 
+    GObject.signal_new('collapse-all', Gtk.TreeView, GObject.SIGNAL_ACTION,
+                       GObject.TYPE_BOOLEAN, ())
+
     css_file = os.path.join(meld.conf.DATADIR, "meld.css")
     provider = Gtk.CssProvider()
     try:
diff --git a/data/meld.css b/data/meld.css
index 8aa1251..afbe342 100644
--- a/data/meld.css
+++ b/data/meld.css
@@ -27,3 +27,11 @@ LinkMap {
     background-image: none;
     background-color: rgb(237, 54, 54);
 }
+
+ binding-set tree-view-collapse-all {
+    bind "underscore" { "collapse-all" () };
+}
+
+GtkTreeView {
+    gtk-key-bindings: tree-view-collapse-all;
+}
diff --git a/data/ui/dirdiff.ui b/data/ui/dirdiff.ui
index 5624705..4eea18b 100644
--- a/data/ui/dirdiff.ui
+++ b/data/ui/dirdiff.ui
@@ -367,6 +367,7 @@
                         <signal name="row-activated" handler="on_treeview_row_activated" swapped="no"/>
                         <signal name="row-collapsed" handler="on_treeview_row_collapsed" swapped="no"/>
                         <signal name="popup-menu" handler="on_treeview_popup_menu" swapped="no"/>
+                        <signal name="collapse-all" handler="on_treeview_collapse_all" swapped="no"/>
                         <child internal-child="selection">
                           <object class="GtkTreeSelection" id="treeview-selection1"/>
                         </child>
@@ -423,6 +424,7 @@
                         <signal name="row-activated" handler="on_treeview_row_activated" swapped="no"/>
                         <signal name="row-collapsed" handler="on_treeview_row_collapsed" swapped="no"/>
                         <signal name="popup-menu" handler="on_treeview_popup_menu" swapped="no"/>
+                        <signal name="collapse-all" handler="on_treeview_collapse_all" swapped="no"/>
                         <child internal-child="selection">
                           <object class="GtkTreeSelection" id="treeview-selection2"/>
                         </child>
@@ -479,6 +481,7 @@
                         <signal name="row-activated" handler="on_treeview_row_activated" swapped="no"/>
                         <signal name="row-collapsed" handler="on_treeview_row_collapsed" swapped="no"/>
                         <signal name="popup-menu" handler="on_treeview_popup_menu" swapped="no"/>
+                        <signal name="collapse-all" handler="on_treeview_collapse_all" swapped="no"/>
                         <child internal-child="selection">
                           <object class="GtkTreeSelection" id="treeview-selection3"/>
                         </child>
diff --git a/meld/dirdiff.py b/meld/dirdiff.py
index e5db9ef..84dc642 100644
--- a/meld/dirdiff.py
+++ b/meld/dirdiff.py
@@ -1174,6 +1174,10 @@ class DirDiff(melddoc.MeldDoc, gnomeglade.Component):
         self._do_to_others(view, self.treeview, "collapse_row", (path,))
         self._update_diffmaps()
 
+    def on_treeview_collapse_all(self, view, *rest):
+        for path in sorted(self.row_expansions, key=len, reverse=True):
+            view.collapse_row(Gtk.TreePath.new_from_string(path))
+
     def on_popup_deactivate_event(self, popup):
         for (treeview, inid, outid) in zip(self.treeview, self.focus_in_events, self.focus_out_events):
             treeview.handler_unblock(inid)