diff --git a/conf/spark-env.sh.template b/conf/spark-env.sh.template
index b7c985ace69cf64b42e2529cc40a5720afde6d70..b9aab5a3712c4e22a51182768c755e5d523efde7 100755
--- a/conf/spark-env.sh.template
+++ b/conf/spark-env.sh.template
@@ -34,6 +34,7 @@
 
 # Options read in YARN client mode
 # - HADOOP_CONF_DIR, to point Spark towards Hadoop configuration files
+# - YARN_CONF_DIR, to point Spark towards YARN configuration files when you use YARN
 # - SPARK_EXECUTOR_CORES, Number of cores for the executors (Default: 1).
 # - SPARK_EXECUTOR_MEMORY, Memory per Executor (e.g. 1000M, 2G) (Default: 1G)
 # - SPARK_DRIVER_MEMORY, Memory for Driver (e.g. 1000M, 2G) (Default: 1G)