diff --git a/nginx.sh b/nginx.sh
index 58ac785..20f6bac 100644
--- a/nginx.sh
+++ b/nginx.sh
@@ -39,6 +39,16 @@ else
     exit 1
 fi
 
+# Exit if variables are missing
+for var in eff_email_address appname domain host port
+do
+    if [ -z ${!var} ]
+    then
+        echo "Variable ${var} does not exist, aborting..."
+        exit 1
+    fi
+done
+
 # Add backup directive to nginx.conf if supplied
 if [ ${backup_port} ]
 then