diff --git a/ooRexx.spec b/ooRexx.spec
index b017a76..da3c235 100644
--- a/ooRexx.spec
+++ b/ooRexx.spec
@@ -63,6 +63,10 @@ tar -C src -xvzf %{SOURCE0}
 
 %build
 cd build
+
+# reproducible builds: https://sourceforge.net/p/oorexx/bugs/1712/
+setarch -R
+
 # FIXME: you should use the %%cmake macros
 cmake -S ../src -DORX_REXXPATH=%{_rexxpath} -DORX_SHEBANG=%{_bindir}/rexx -DBUILD_RPM=1 -DCMAKE_INSTALL_PREFIX=%{_prefix}
 %make_build -O -j 2