diff --git a/yggdrasil.sh b/yggdrasil.sh
index 68caca9..45e89e3 100755
--- a/yggdrasil.sh
+++ b/yggdrasil.sh
@@ -11,21 +11,21 @@
 # include functions and vars from external files
 #
 dir=$(dirname $0)
-source /opt/yggdrasil/vars.sh
-source /opt/yggdrasil/core_functions.sh
-source /opt/yggdrasil/tools_functions.sh
+source /opt/yggdrasil/vars.sh || exit 1
+source /opt/yggdrasil/core_functions.sh || exit 1
+source /opt/yggdrasil/tools_functions.sh || exit 1
 
 OS=`lsb_release -d | awk -F':' '{print $2}' | awk -F'\t' '{print $2}'`
 case $OS in
   *"Ubuntu 16.04"* | *"Linux Mint 18"*)
-    source /opt/yggdrasil/repo_functions_ub1604.sh
-    source /opt/yggdrasil/install_functions_ub1604.sh
-    source /opt/yggdrasil/menus_functions_ub1604.sh
+    source /opt/yggdrasil/repo_functions_ub1604.sh || exit 1
+    source /opt/yggdrasil/install_functions_ub1604.sh || exit 1
+    source /opt/yggdrasil/menus_functions_ub1604.sh || exit 1
     ;;
   *"Ubuntu 18.04"* | *"Linux Mint 19"*)
-    source /opt/yggdrasil/repo_functions_ub1804.sh
-    source /opt/yggdrasil/install_functions_ub1804.sh
-    source /opt/yggdrasil/menus_functions_ub1804.sh
+    source /opt/yggdrasil/repo_functions_ub1804.sh || exit 1
+    source /opt/yggdrasil/install_functions_ub1804.sh || exit 1
+    source /opt/yggdrasil/menus_functions_ub1804.sh || exit 1
     ;;
   *)
     printf "\n"