diff --git a/pkgs/tools/X11/wmctrl/64-bit-data.patch b/pkgs/tools/X11/wmctrl/64-bit-data.patch
new file mode 100644
index 00000000000..3ec1c913ffe
--- /dev/null
+++ b/pkgs/tools/X11/wmctrl/64-bit-data.patch
@@ -0,0 +1,32 @@
+Description: Correct 64 Architecture implementation of 32 bit data
+Author: Chris Donoghue <cdonoghu@gmail.com>
+Bug-Debian: http://bugs.debian.org/362068
+
+--- wmctrl-1.07.orig/main.c
++++ wmctrl-1.07/main.c
+@@ -1425,6 +1425,16 @@ static gchar *get_property (Display *dis
+      *
+      * long_length = Specifies the length in 32-bit multiples of the
+      *               data to be retrieved.
++     *
++     * NOTE:  see 
++     * http://mail.gnome.org/archives/wm-spec-list/2003-March/msg00067.html
++     * In particular:
++     *
++     * 	When the X window system was ported to 64-bit architectures, a
++     * rather peculiar design decision was made. 32-bit quantities such
++     * as Window IDs, atoms, etc, were kept as longs in the client side
++     * APIs, even when long was changed to 64 bits.
++     *
+      */
+     if (XGetWindowProperty(disp, win, xa_prop_name, 0, MAX_PROPERTY_VALUE_LEN / 4, False,
+             xa_prop_type, &xa_ret_type, &ret_format,     
+@@ -1441,6 +1451,8 @@ static gchar *get_property (Display *dis
+ 
+     /* null terminate the result to make string handling easier */
+     tmp_size = (ret_format / 8) * ret_nitems;
++    /* Correct 64 Architecture implementation of 32 bit data */
++    if(ret_format==32) tmp_size *= sizeof(long)/4;
+     ret = g_malloc(tmp_size + 1);
+     memcpy(ret, ret_prop, tmp_size);
+     ret[tmp_size] = '\0';
diff --git a/pkgs/tools/X11/wmctrl/default.nix b/pkgs/tools/X11/wmctrl/default.nix
index f4705bdb0d4..3f691b8ecd4 100644
--- a/pkgs/tools/X11/wmctrl/default.nix
+++ b/pkgs/tools/X11/wmctrl/default.nix
@@ -11,6 +11,8 @@ stdenv.mkDerivation rec {
  
   buildInputs = [ libX11 libXmu glib pkgconfig ];
 
+  patches = [ ./64-bit-data.patch ];
+
   meta = {
     homepage = http://tomas.styblo.name/wmctrl/;
     description = "wmctrl is a UNIX/Linux command line tool to interact with an EWMH/NetWM compatible X Window Manager";