diff --git a/setup.sh b/setup.sh
index b5d4e6f..99e409d 100755
--- a/setup.sh
+++ b/setup.sh
@@ -16,7 +16,10 @@ then
 fi
 
 check() {
-    read -r -p "$1" ANSWER
+    while ! [[ "${ANSWER}" =~ ^[YyNn] ]]
+    do
+        read -r -p "$1" ANSWER
+    done
     if [[ "${ANSWER}" =~ ^[Yy] ]]
     then
         return 0