diff --git a/xmobar-0.15-mtl-2.1.patch b/xmobar-0.15-mtl-2.1.patch
new file mode 100644
index 0000000..591a81c
--- /dev/null
+++ b/xmobar-0.15-mtl-2.1.patch
@@ -0,0 +1,12 @@
+diff -up xmobar-0.15/xmobar.cabal~ xmobar-0.15/xmobar.cabal
+--- xmobar-0.15/xmobar.cabal~	2012-06-04 09:55:49.000000000 +0900
++++ xmobar-0.15/xmobar.cabal	2012-06-11 12:35:33.020448077 +0900
+@@ -112,7 +112,7 @@ executable xmobar
+       time,
+       filepath,
+       X11 == 1.6.*,
+-      mtl == 2.0.*,
++      mtl >= 2.0 && <2.2,
+       parsec == 3.1.*,
+       stm == 2.3.*
+ 
diff --git a/xmobar.spec b/xmobar.spec
index f5ce3c9..d5cc5c0 100644
--- a/xmobar.spec
+++ b/xmobar.spec
@@ -23,6 +23,7 @@ BuildRequires:  ghc-rpm-macros
 # END cabal2spec
 Source1:        xmobar.desktop
 Patch1:         xmobar-0.13-default-fonts.patch
+Patch2:         xmobar-0.15-mtl-2.1.patch
 
 %if %{with alsa}
 BuildRequires:  ghc-alsa-mixer-devel
@@ -62,6 +63,7 @@ color management, output templates, and extensibility through plugins.
 %prep
 %setup -q
 %patch1 -p1 -b .fonts
+%patch2 -p1 -b .orig
 
 
 %build
@@ -90,6 +92,7 @@ install --mode=0755 -p samples/xmonadpropwrite %{buildroot}%{_bindir}/xmonadprop
 %changelog
 * Mon Jun 11 2012 Jens Petersen <petersen@redhat.com> - 0.15-1
 - update to 0.15
+- allow building with mtl-2.1
 - xmobar-0.14-MPD-ghc74-Show.patch no longer needed
 
 * Wed Mar 21 2012 Jens Petersen <petersen@redhat.com> - 0.14-4