diff --git a/project_euler/problem_007/sol1.rb b/project_euler/problem_007/sol1.rb
index 20f14c6..44bacca 100644
--- a/project_euler/problem_007/sol1.rb
+++ b/project_euler/problem_007/sol1.rb
@@ -24,8 +24,7 @@ def is_prime?(number)
     result = value
 end
 
-def solution?()
-  nth = 10001
+def solution(nth = 10001)
   primes = Array.new()
   num = 2
   while primes.length < nth
@@ -37,5 +36,5 @@ def solution?()
   primes[primes.length - 1]
 end
 
-answer = solution?()
+answer = solution()
 p answer
\ No newline at end of file