diff --git a/matrix-synapse.spec b/matrix-synapse.spec
index eb2d55b..126e0a8 100644
--- a/matrix-synapse.spec
+++ b/matrix-synapse.spec
@@ -131,7 +131,7 @@ ln -s /usr/sbin/service %{buildroot}%{_sbindir}/rcsynapse
 %{__mkdir_p} "%{buildroot}%{_rundir}/synapse"
 %{__mkdir_p} "%{buildroot}%{_rundir}/synapse"
 %{__mkdir_p} "%{buildroot}%{_rundir}/synapse"
-%fdupes %{buildroot}%{_prefix}
+%python_expand %fdupes %{buildroot}%{$python_sitelib}
 
 %clean
 rm -rf %{buildroot}