diff --git a/build-k4.sh b/build-k4.sh
index f7e7560497b51e2dae4bbf8a3e6ecd0611d3c535..efec2f5ffbe172d1ad611b20c46eb4f0c32f8d8e 100755
--- a/build-k4.sh
+++ b/build-k4.sh
@@ -20,7 +20,8 @@ function error:() {
 }
 
 function check-cepcsw-envvar() {
-    source /cvmfs/sw.hsf.org/key4hep/setup.sh
+    # source /cvmfs/sw.hsf.org/key4hep/setup.sh
+    source /cvmfs/sw-nightlies.hsf.org/key4hep/setup.sh
     # fix the order of compiler
     local ccdir=$(dirname $CC)
     export PATH=$ccdir:$PATH