diff --git a/d01.sh b/d01.sh
index df37546..75a94d1 100755
--- a/d01.sh
+++ b/d01.sh
@@ -5,7 +5,7 @@ while read line; do
     num1="$(echo "$line" | sed -n 's/^[^0-9]*\([0-9]\).*/\1/p')"
     num2="$(echo "$line" | sed -n 's/.*\([0-9]\)[^0-9]*$/\1/p')"
     sum=$(( $sum + $num1$num2 ))
-done < d01_input.txt
+done < "$1"
 echo "$sum"
 
 sum=0
@@ -35,5 +35,5 @@ while read line; do
     num1="$(echo "$line1" | sed -n 's/^[^0-9]*\([0-9]\).*/\1/p')"
     num2="$(echo "$line2" | sed -n 's/.*\([0-9]\)[^0-9]*$/\1/p')"
     sum=$(( $sum + $num1$num2 ))
-done < d01_input.txt
+done < "$1"
 echo "$sum"