diff --git a/ghc-snap-core.spec b/ghc-snap-core.spec
index 1eee091..8a67234 100644
--- a/ghc-snap-core.spec
+++ b/ghc-snap-core.spec
@@ -46,6 +46,7 @@ BuildRequires:  ghc-unordered-containers-devel
 BuildRequires:  ghc-vector-devel
 BuildRequires:  ghc-zlib-enum-devel
 # End cabal-rpm deps
+Patch1:         snap-core-0.9.2.2-portable-flag.patch
 
 %description
 %{common_description}
@@ -53,6 +54,7 @@ BuildRequires:  ghc-zlib-enum-devel
 
 %prep
 %setup -q -n %{pkg_name}-%{version}
+%patch1 -p1 -b .orig
 
 
 %build
@@ -86,6 +88,7 @@ BuildRequires:  ghc-zlib-enum-devel
 %changelog
 * Mon Oct 29 2012 Jens Petersen <petersen@redhat.com> - 0.9.2.2-1
 - update to 0.9.2.2
+- compile in portable cross-platform mode until bytestring-mmap packaged
 
 * Thu Jul 19 2012 Fedora Release Engineering <rel-eng@lists.fedoraproject.org> - 0.9.0-4
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_18_Mass_Rebuild
diff --git a/snap-core-0.9.2.2-portable-flag.patch b/snap-core-0.9.2.2-portable-flag.patch
new file mode 100644
index 0000000..bc4216f
--- /dev/null
+++ b/snap-core-0.9.2.2-portable-flag.patch
@@ -0,0 +1,11 @@
+--- snap-core-0.9.2.2/snap-core.cabal~	2012-10-09 02:24:54.000000000 +0900
++++ snap-core-0.9.2.2/snap-core.cabal	2012-10-29 18:00:48.906120240 +0900
+@@ -72,7 +72,7 @@
+ Flag portable
+   Description: Compile in cross-platform mode. No platform-specific code or
+                optimizations such as C routines will be used.
+-  Default: False
++  Default: True
+ 
+ 
+ Flag debug