diff --git a/trojita.spec b/trojita.spec
index 9fdeef1..e6cba4b 100644
--- a/trojita.spec
+++ b/trojita.spec
@@ -98,9 +98,12 @@ help2man -o %{buildroot}%{_mandir}/man1/%{name}.1 --no-info --no-discard-stderr 
 desktop-file-validate %{buildroot}%{_datadir}/applications/%{name}.desktop
 # appstream is not available at EPEL
 appstream-util validate-relax --nonet %{buildroot}%{_datadir}/appdata/%{name}.appdata.xml ||:
-# do tests in some fake X 
-CTEST_OUTPUT_ON_FAILURE=BOOL:ON xvfb-run ctest %{?_smp_mflags} --output-on-failure -VV 
-
+# do tests in some fake X, we can not use xvfb-run cause it fails at koji
+export DISPLAY=%{X_display}
+Xvfb %{X_display} &
+trap "kill $! || true" EXIT
+export CTEST_OUTPUT_ON_FAILURE=BOOL:ON
+ctest %{?_smp_mflags} --output-on-failure -VV 
 
 %post
 /bin/touch --no-create %{_datadir}/icons/hicolor &>/dev/null || :