diff --git a/Library/Homebrew/utils/repology.rb b/Library/Homebrew/utils/repology.rb
index dc0a14f78a2f0eed0acdc7aa5590383eab49601d..8f15814505ab03ad65e040d9002579911070682f 100644
--- a/Library/Homebrew/utils/repology.rb
+++ b/Library/Homebrew/utils/repology.rb
@@ -45,7 +45,7 @@ module Repology
       last_package_index = outdated_packages.size - 1
     end
 
-    outdated_packages = outdated_packages.first(limit) if outdated_packages.size > limit
+    outdated_packages = outdated_packages.first(limit) if !limit.nil? && outdated_packages.size > limit
 
     puts "#{outdated_packages.size} outdated #{"package".pluralize(outdated_packages.size)} found"
     puts