diff --git a/Femto-DS/Femto-DS.sh b/Femto-DS/Femto-DS.sh
index 5f55a620f2981aeb9c44fad2c9c934aa744580d0..785f8797025565a359b12d93da01a135f2e88ae6 100755
--- a/Femto-DS/Femto-DS.sh
+++ b/Femto-DS/Femto-DS.sh
@@ -10,6 +10,7 @@ if [ ${#} -eq 1 ]; then
     instance="${1}"
 else
     echo "The instance of this device server must be provided!"
+    exit -1
 fi
 containerPath=${myDir//${HOME}\//\/hosthome\/}
 docker exec -it itango python3 ${containerPath}/${runThis} ${instance}
diff --git a/RandomData-DS/RandomData-DS.sh b/RandomData-DS/RandomData-DS.sh
index 5f55a620f2981aeb9c44fad2c9c934aa744580d0..785f8797025565a359b12d93da01a135f2e88ae6 100755
--- a/RandomData-DS/RandomData-DS.sh
+++ b/RandomData-DS/RandomData-DS.sh
@@ -10,6 +10,7 @@ if [ ${#} -eq 1 ]; then
     instance="${1}"
 else
     echo "The instance of this device server must be provided!"
+    exit -1
 fi
 containerPath=${myDir//${HOME}\//\/hosthome\/}
 docker exec -it itango python3 ${containerPath}/${runThis} ${instance}