diff --git a/darshan-test/regression/bg-profile-conf-alcf/runjob.sh b/darshan-test/regression/bg-profile-conf-alcf/runjob.sh
index 37db7f94fcf2a0023a49bb7bfe545e4d0b67cf0f..ec665fc83ce3c0b5a410f7d0dbc0adbda6fbec9b 100755
--- a/darshan-test/regression/bg-profile-conf-alcf/runjob.sh
+++ b/darshan-test/regression/bg-profile-conf-alcf/runjob.sh
@@ -1,8 +1,8 @@
 #!/bin/bash
 
 # convert DXT env setting
-if [ -n $DXT_ENABLE_IO_TRACE ]; then
-	DXT_ENV="--env DXT_ENABLE_IO_TRACE="
+if [ -n "${DXT_ENABLE_IO_TRACE+defined}" ]; then
+	DXT_ENV="--env DXT_ENABLE_IO_TRACE=$DXT_ENABLE_IO_TRACE"
 fi
 
 # submit job and get job id