diff -Naur xfwm4-4.5.91-orig/defaults/defaults xfwm4-4.5.91/defaults/defaults
--- xfwm4-4.5.91-orig/defaults/defaults	2008-10-10 00:42:42.000000000 +0200
+++ xfwm4-4.5.91/defaults/defaults	2008-11-01 16:52:26.539539519 +0100
@@ -19,6 +19,7 @@
 frame_opacity=100
 full_width_title=true
 inactive_opacity=100
+invert_scroll_workspaces=false
 keytheme=Default
 maximized_offset=0
 move_opacity=100
diff -Naur xfwm4-4.5.91-orig/settings-dialogs/tweaks-settings.c xfwm4-4.5.91/settings-dialogs/tweaks-settings.c
--- xfwm4-4.5.91-orig/settings-dialogs/tweaks-settings.c	2008-10-13 13:39:21.000000000 +0200
+++ xfwm4-4.5.91/settings-dialogs/tweaks-settings.c	2008-11-01 16:50:16.328812562 +0100
@@ -110,6 +110,12 @@
 }
 
 static void
+cb_scroll_workspaces_toggled (GtkToggleButton *toggle, GtkWidget *invert)
+{
+    gtk_widget_set_sensitive (invert, gtk_toggle_button_get_active (toggle));
+}
+
+static void
 cb_activate_placement_center_radio_toggled (GtkToggleButton *toggle, XfconfChannel *channel)
 {
     if (gtk_toggle_button_get_active (toggle))
@@ -165,6 +171,7 @@
 
     /* Workspaces tab */
     GtkWidget *scroll_workspaces_check = glade_xml_get_widget (gxml, "scroll_workspaces_check");
+    GtkWidget *invert_scroll_workspaces_check = glade_xml_get_widget (gxml, "invert_scroll_workspaces_check");
     GtkWidget *toggle_workspaces_check = glade_xml_get_widget (gxml, "toggle_workspaces_check");
     GtkWidget *wrap_layout_check = glade_xml_get_widget (gxml, "wrap_layout_check");
     GtkWidget *wrap_cycle_check = glade_xml_get_widget (gxml, "wrap_cycle_check");
@@ -249,6 +256,12 @@
                       G_CALLBACK (cb_prevent_focus_stealing_check_button_toggled),
                       prevent_focus_stealing_box);
 #endif
+
+    g_signal_connect (G_OBJECT (scroll_workspaces_check),
+                      "toggled",
+                      G_CALLBACK (cb_scroll_workspaces_toggled),
+                      invert_scroll_workspaces_check);
+
     g_signal_connect (G_OBJECT (placement_center_option),
                       "toggled",
                       G_CALLBACK (cb_activate_placement_center_radio_toggled),
@@ -327,6 +340,10 @@
                             G_TYPE_BOOLEAN,
                             (GObject *)scroll_workspaces_check, "active");
     xfconf_g_property_bind (xfwm4_channel,
+                            "/general/invert_scroll_workspaces",
+                            G_TYPE_BOOLEAN,
+                            (GObject *)invert_scroll_workspaces_check, "active");
+    xfconf_g_property_bind (xfwm4_channel,
                             "/general/wrap_layout",
                             G_TYPE_BOOLEAN,
                             (GObject *)wrap_layout_check, "active");
diff -Naur xfwm4-4.5.91-orig/settings-dialogs/xfwm4-tweaks-dialog.glade xfwm4-4.5.91/settings-dialogs/xfwm4-tweaks-dialog.glade
--- xfwm4-4.5.91-orig/settings-dialogs/xfwm4-tweaks-dialog.glade	2008-10-10 00:42:41.000000000 +0200
+++ xfwm4-4.5.91/settings-dialogs/xfwm4-tweaks-dialog.glade	2008-11-01 16:50:02.740533621 +0100
@@ -377,6 +377,29 @@
                   </packing>
                 </child>
                 <child>
+                  <widget class="GtkAlignment" id="scroll_alignment">
+                    <property name="visible">True</property>
+                    <property name="bottom_padding">6</property>
+                    <property name="left_padding">12</property>
+                    <child>
+                      <widget class="GtkCheckButton" id="invert_scroll_workspaces_check">
+                        <property name="visible">True</property>
+                        <property name="sensitive">False</property>
+                        <property name="can_focus">True</property>
+                        <property name="label" translatable="yes">_Invert mouse wheel workspace switching direction</property>
+                        <property name="use_underline">True</property>
+                        <property name="response_id">0</property>
+                        <property name="draw_indicator">True</property>
+                      </widget>
+                    </child>
+                  </widget>
+                  <packing>
+                    <property name="expand">False</property>
+                    <property name="fill">False</property>
+                    <property name="position">1</property>
+                  </packing>
+                </child>
+                <child>
                   <widget class="GtkCheckButton" id="toggle_workspaces_check">
                     <property name="visible">True</property>
                     <property name="can_focus">True</property>
@@ -389,7 +412,7 @@
                   <packing>
                     <property name="expand">False</property>
                     <property name="fill">False</property>
-                    <property name="position">1</property>
+                    <property name="position">2</property>
                   </packing>
                 </child>
                 <child>
@@ -404,7 +427,7 @@
                   <packing>
                     <property name="expand">False</property>
                     <property name="fill">False</property>
-                    <property name="position">2</property>
+                    <property name="position">3</property>
                   </packing>
                 </child>
                 <child>
@@ -419,7 +442,7 @@
                   <packing>
                     <property name="expand">False</property>
                     <property name="fill">False</property>
-                    <property name="position">3</property>
+                    <property name="position">4</property>
                   </packing>
                 </child>
               </widget>
diff -Naur xfwm4-4.5.91-orig/src/events.c xfwm4-4.5.91/src/events.c
--- xfwm4-4.5.91-orig/src/events.c	2008-10-14 10:10:49.000000000 +0200
+++ xfwm4-4.5.91/src/events.c	2008-11-01 16:52:47.659991662 +0100
@@ -835,11 +835,13 @@
 
     if (ev->button == Button4)
     {
-        workspaceSwitch (screen_info, screen_info->current_ws - 1, NULL, TRUE, ev->time);
+        workspaceSwitch (screen_info, screen_info->current_ws - (screen_info->params->invert_scroll_workspaces ? -1 : 1), NULL, TRUE, ev->time);
+
     }
     else if (ev->button == Button5)
     {
-        workspaceSwitch (screen_info, screen_info->current_ws + 1, NULL, TRUE, ev->time);
+        workspaceSwitch (screen_info, screen_info->current_ws + (screen_info->params->invert_scroll_workspaces ? -1 : 1), NULL, TRUE, ev->time);
+
     }
 }
 
diff -Naur xfwm4-4.5.91-orig/src/settings.c xfwm4-4.5.91/src/settings.c
--- xfwm4-4.5.91-orig/src/settings.c	2008-10-10 00:42:42.000000000 +0200
+++ xfwm4-4.5.91/src/settings.c	2008-11-01 16:54:54.438644152 +0100
@@ -655,6 +655,7 @@
         {"inactive_hilight_2", NULL, G_TYPE_STRING, FALSE},
         {"inactive_shadow_2", NULL, G_TYPE_STRING, FALSE},
         {"inactive_mid_2", NULL, G_TYPE_STRING, FALSE},
+        {"invert_scroll_workspaces", NULL, G_TYPE_BOOLEAN, FALSE},
         /* You can change the order of the following parameters */
         {"activate_action", NULL, G_TYPE_STRING, TRUE},
         {"borderless_maximize", NULL, G_TYPE_BOOLEAN, TRUE},
@@ -677,6 +678,7 @@
         {"frame_opacity", NULL, G_TYPE_INT, TRUE},
         {"full_width_title", NULL, G_TYPE_BOOLEAN, TRUE},
         {"inactive_opacity", NULL, G_TYPE_INT, TRUE},
+        {"invert_scroll_workspaces", NULL, G_TYPE_BOOLEAN, FALSE},
         {"keytheme", NULL, G_TYPE_STRING, TRUE},
         {"margin_bottom", NULL, G_TYPE_INT, FALSE},
         {"margin_left", NULL, G_TYPE_INT, FALSE},
@@ -933,6 +935,8 @@
         getBoolValue ("wrap_cycle", rc);
     screen_info->params->scroll_workspaces =
         getBoolValue ("scroll_workspaces", rc);
+    screen_info->params->invert_scroll_workspaces =
+        getBoolValue ("invert_scroll_workspaces", rc);
     screen_info->params->wrap_resistance =
         getIntValue ("wrap_resistance", rc);
 
@@ -1327,6 +1331,10 @@
                 {
                     screen_info->params->scroll_workspaces = g_value_get_boolean (value);
                 }
+                else if (!strcmp (name, "invert_scroll_workspaces"))
+                {
+                    screen_info->params->invert_scroll_workspaces = g_value_get_boolean (value);
+                }
                 else if (!strcmp (name, "toggle_workspaces"))
                 {
                     screen_info->params->toggle_workspaces = g_value_get_boolean (value);
diff -Naur xfwm4-4.5.91-orig/src/settings.h xfwm4-4.5.91/src/settings.h
--- xfwm4-4.5.91-orig/src/settings.h	2008-10-10 00:42:42.000000000 +0200
+++ xfwm4-4.5.91/src/settings.h	2008-11-01 16:53:16.000579394 +0100
@@ -200,6 +200,7 @@
     gboolean focus_hint;
     gboolean focus_new;
     gboolean full_width_title;
+    gboolean invert_scroll_workspaces;
     gboolean prevent_focus_stealing;
     gboolean raise_on_click;
     gboolean raise_on_focus;