diff --git a/artiq-zynq.nix b/artiq-zynq.nix
index ec2024c..1f720d9 100644
--- a/artiq-zynq.nix
+++ b/artiq-zynq.nix
@@ -55,7 +55,7 @@ in
 
           export USER=hydra
           export OPENOCD_ZYNQ=${artiq-zynq.zynq-rs}/openocd
-          export SZL=${artiq-zynq.zynq-rs.zc706-szl}/szl.elf
+          export SZL=${(import artiq-zynq.zynq-rs).zc706-szl}/szl.elf
           pushd ${<artiq-zynq>}
           bash ${<artiq-zynq>}/remote_run.sh -h rpi-4 -o "$NIX_SSHOPTS" -d ${artiq-zynq.zc706-nist_qc2-jtag}
           popd