diff --git a/guitarix-0.25.1-no-x86.patch b/guitarix-0.25.1-no-x86.patch
new file mode 100644
index 0000000..b912235
--- /dev/null
+++ b/guitarix-0.25.1-no-x86.patch
@@ -0,0 +1,32 @@
+diff -up guitarix-0.25.1/src/LV2/gxamp.lv2/StereoAmp/wscript.no-x86 guitarix-0.25.1/src/LV2/gxamp.lv2/StereoAmp/wscript
+--- guitarix-0.25.1/src/LV2/gxamp.lv2/StereoAmp/wscript.no-x86	2013-01-15 12:11:00.000000000 +0100
++++ guitarix-0.25.1/src/LV2/gxamp.lv2/StereoAmp/wscript	2013-01-15 12:16:05.000000000 +0100
+@@ -31,15 +31,13 @@ def build(bld):
+         src2.append('../../../zita-resampler-1.1.0/resampler-table.cc')
+         incl2.append('../../../zita-resampler-1.1.0')
+     cxxflag1 =[]
+-    if not bld.env['OPT']:
+-        cxxflag2 = [ "-msse2", "-mfpmath=sse"]
+     lv2_plugin_stereo = bld(
+         features='cxx cshlib ',
+         includes = incl2,
+         lib = lib2,
+         uselib = uselib2,
+         obj_ext  = '_3.o',
+-        cxxflags = cxxflag2,
++        cxxflags = cxxflag1,
+         defines  = ["LV2_SO"],
+         target   = 'gxamp_stereo',
+         source   = src2,
+diff -up guitarix-0.25.1/src/LV2/gxamp.lv2/wscript.no-x86 guitarix-0.25.1/src/LV2/gxamp.lv2/wscript
+--- guitarix-0.25.1/src/LV2/gxamp.lv2/wscript.no-x86	2013-01-15 11:59:19.000000000 +0100
++++ guitarix-0.25.1/src/LV2/gxamp.lv2/wscript	2013-01-15 11:59:32.000000000 +0100
+@@ -31,8 +31,6 @@ def build(bld):
+         src.append('../../zita-resampler-1.1.0/resampler-table.cc')
+         incl.append('../../zita-resampler-1.1.0')
+     cxxflag =[]
+-    if not bld.env['OPT']:
+-        cxxflag = [ "-msse2", "-mfpmath=sse"]
+     lv2_plugin = bld(
+         features='cxx cshlib ',
+         includes = incl,
diff --git a/guitarix.spec b/guitarix.spec
index c10c567..47d74b7 100644
--- a/guitarix.spec
+++ b/guitarix.spec
@@ -5,7 +5,7 @@
 
 Name:           guitarix
 Version:        0.25.1
-Release:        3%{?dist}
+Release:        4%{?dist}
 Summary:        Mono amplifier to JACK
 Group:          Applications/Multimedia
 License:        GPLv2+
@@ -14,6 +14,8 @@ Source0:        http://sourceforge.net/projects/%{name}/files/%{name}/%{altname2
 Patch0:         guitarix-0.25.1-lv2dir.patch
 Patch1:         guitarix-0.25.1-shared-lib.patch
 Patch2:         guitarix-0.25.1-pkgconfig.patch
+# gxamp should use inherited compiler flags
+Patch3:         guitarix-0.25.1-no-x86.patch
 
 BuildRequires:  desktop-file-utils
 BuildRequires:  faust
@@ -135,11 +137,12 @@ guitarix, but can also be used by any other ladspa host.
 %patch0 -p2
 %patch1 -p2
 %patch2 -p2
+%patch3 -p1
 
 # The build system does not use these bundled libraries by default. But
 # just to make sure:
 rm -fr src/zita-convolver src/zita-resampler
-sed -i -e 's|-O3|%{optflags}|' wscript
+sed -i -e 's|-O3||' wscript
 
 %build
 ./waf -vv configure --prefix=%{_prefix} --libdir=%{_libdir}                  \
@@ -221,6 +224,10 @@ chmod 755 %{buildroot}%{_libdir}/glade/modules/libgladegx.so
 %{_libdir}/lv2/*
 
 %changelog
+* Tue Jan 15 2013 Dan Horák <dan[at]danny.cz> 0.25.1-4
+- fix build on non-x86 arches (gxamp shouldn't append x86-only flags)
+- set %%{optflags} only once
+
 * Sun Jan 13 2013 Brendan Jones <brendan.jones.it@gmail.com> 0.25.1-3
 - Add missing BR lv2-devel