diff --git a/check_rebootrequired.sh b/check_rebootrequired.sh
index a497687..acd7cc2 100755
--- a/check_rebootrequired.sh
+++ b/check_rebootrequired.sh
@@ -6,8 +6,28 @@ if [ ! -f "$INPUT" ]; then
 fi
 
 NUM_LINES=`cat "$INPUT" | wc -l`
-echo "WARNING: $NUM_LINES packages require a reboot:"
-cat "$INPUT"
 
-exit 1
+case $NUM_LINES in
+	0)
+		echo "UNKNOWN: $INPUT is empty"
+		exit 4
+		;;
+	1)
+		echo "WARNING: $NUM_LINES package requires a reboot:"
+		cat "$INPUT"
+		exit 1
+		;;
+	[2-9]*)
+		echo "WARNING: $NUM_LINES packages require a reboot:"
+		cat "$INPUT"
+		exit 1
+		;;
+	*)
+		echo "UNKNOWN: Unexpected output of 'wc': $NUM_LINES"
+		exit 4
+		;;
+		
+esac
+
+