diff --git a/bin/spark-class b/bin/spark-class
index e38e08dec40e4f06d4e33ac76bec2eb439179eb7..8cae6ccbabe7c1b4b4a5698414a0d68f6942d62d 100755
--- a/bin/spark-class
+++ b/bin/spark-class
@@ -42,6 +42,7 @@ else
   ASSEMBLY_DIR="$SPARK_HOME/assembly/target/scala-$SPARK_SCALA_VERSION"
 fi
 
+GREP_OPTIONS=
 num_jars="$(ls -1 "$ASSEMBLY_DIR" | grep "^spark-assembly.*hadoop.*\.jar$" | wc -l)"
 if [ "$num_jars" -eq "0" -a -z "$SPARK_ASSEMBLY_JAR" -a "$SPARK_PREPEND_CLASSES" != "1" ]; then
   echo "Failed to find Spark assembly in $ASSEMBLY_DIR." 1>&2