diff --git a/sbin/spark-daemon.sh b/sbin/spark-daemon.sh
index 28d205f03e0f..b7233e6e9bf3 100755
--- a/sbin/spark-daemon.sh
+++ b/sbin/spark-daemon.sh
@@ -98,6 +98,10 @@ spark_rotate_log ()
 . "${SPARK_HOME}/bin/load-spark-env.sh"
 
 if [ "$SPARK_IDENT_STRING" = "" ]; then
+  # if for some reason the shell doesn't have $USER defined
+  # (e.g., ssh'd in to execute a command)
+  # let's get the effective username and use that
+  USER=${USER:-$(id -nu)}
   export SPARK_IDENT_STRING="$USER"
 fi