diff --git a/bin/spark-class b/bin/spark-class
index 77ea40cc37946..65d3b9612909a 100755
--- a/bin/spark-class
+++ b/bin/spark-class
@@ -72,6 +72,8 @@ build_command() {
   printf "%d\0" $?
 }
 
+# Turn off posix mode since it does not allow process substitution
+set +o posix
 CMD=()
 while IFS= read -d '' -r ARG; do
   CMD+=("$ARG")