diff --git a/project_euler/problem_08/sol1.py b/project_euler/problem_08/sol1.py
index fb5ed25bf..817fd3f87 100644
--- a/project_euler/problem_08/sol1.py
+++ b/project_euler/problem_08/sol1.py
@@ -2,7 +2,7 @@ import sys
 def main():
     LargestProduct = -sys.maxsize-1
     number=input().strip()
-    for i in range(len(number)-13):
+    for i in range(len(number)-12):
         product=1
         for j in range(13):
             product *= int(number[i+j])