diff --git a/.gitignore b/.gitignore
index a06382c..e44b7da 100644
--- a/.gitignore
+++ b/.gitignore
@@ -48,3 +48,5 @@ firefox-3.6.4.source.tar.bz2
 /firefox-langpacks-13.0.1-20120616.tar.xz
 /firefox-14.0.1.source.tar.bz2
 /firefox-langpacks-14.0.1-20120716.tar.xz
+/firefox-15.0.source.tar.bz2
+/firefox-langpacks-15.0-20120827.tar.xz
diff --git a/firefox.spec b/firefox.spec
index 02943e9..b117886 100644
--- a/firefox.spec
+++ b/firefox.spec
@@ -79,6 +79,7 @@ Patch14:        firefox-5.0-asciidel.patch
 Patch15:        firefox-15.0-enable-addons.patch
 
 # Upstream patches
+Patch20:        mozilla-750620.patch
 
 %if %{official_branding}
 # Required by Mozilla Corporation
@@ -123,6 +124,7 @@ cd %{tarballdir}
 %patch15 -p2 -b .addons
 
 # Upstream patches
+%patch20 -p1 -b .750620
 
 %if %{official_branding}
 # Required by Mozilla Corporation
@@ -397,6 +399,9 @@ gtk-update-icon-cache %{_datadir}/icons/hicolor &>/dev/null || :
 * Mon Aug 27 2012 Martin Stransky <stransky@redhat.com> - 15.0-1
 - Update to 15.0
 
+* Wed Aug 22 2012 Dan Horák <dan[at]danny.cz> - 14.0.1-3
+- add fix for secondary arches from xulrunner
+
 * Wed Aug 1 2012 Martin Stransky <stransky@redhat.com> - 14.0.1-2
 - removed StartupWMClass (rhbz#844860)
 
diff --git a/mozilla-750620.patch b/mozilla-750620.patch
new file mode 100644
index 0000000..c8c6d10
--- /dev/null
+++ b/mozilla-750620.patch
@@ -0,0 +1,33 @@
+# HG changeset patch
+# User Mike Hommey <mh+mozilla@glandium.org>
+# Date 1337607752 -7200
+# Node ID 93093285af6065c441a806e97ca8f79225a158c6
+# Parent  87c452c6444eecd226a30458e735d0cfaad714fd
+Bug 750620 - Declare double conversion correctness for more architectures
+
+diff --git a/mfbt/double-conversion/utils.h b/mfbt/double-conversion/utils.h
+--- a/mfbt/double-conversion/utils.h
++++ b/mfbt/double-conversion/utils.h
+@@ -48,17 +48,21 @@
+ // An easy way to test if the floating-point operations are correct is to
+ // evaluate: 89255.0/1e22. If the floating-point stack is 64 bits wide then
+ // the result is equal to 89255e-22.
+ // The best way to test this, is to create a division-function and to compare
+ // the output of the division with the expected result. (Inlining must be
+ // disabled.)
+ // On Linux,x86 89255e-22 != Div_double(89255.0/1e22)
+ #if defined(_M_X64) || defined(__x86_64__) || \
+-    defined(__ARMEL__) || \
++    defined(__ARMEL__) || defined(__avr32__) || \
++    defined(__hppa__) || defined(__ia64__) || \
++    defined(__mips__) || defined(__powerpc__) || \
++    defined(__sparc__) || defined(__s390__) || \
++    defined(__SH4__) || defined(__alpha__) || \
+     defined(_MIPS_ARCH_MIPS32R2)
+ #define DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS 1
+ #elif defined(_M_IX86) || defined(__i386__)
+ #if defined(_WIN32)
+ // Windows uses a 64bit wide floating point stack.
+ #define DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS 1
+ #else
+ #undef DOUBLE_CONVERSION_CORRECT_DOUBLE_OPERATIONS