diff --git a/start.sh b/start.sh
index 2e07adf4..e5772142 100755
--- a/start.sh
+++ b/start.sh
@@ -1,3 +1,12 @@
+
 java -version
+java_version=`java -version 2>&1 | fgrep -i version | cut -d'"' -f2 | sed -e 's/^1\./1\%/' -e 's/\..*//' -e 's/%/./'`
+
+if [[ $java_version -gt 11 ]]  ; then
+  echo "Java version $java_version must not be > 11"
+  exit 1
+fi
+
+
 
 mvn -DskipTests=false  compile dependency:copy-dependencies exec:exec