diff --git a/lib/rubygems/requirement.rb b/lib/rubygems/requirement.rb
index 55a52d750d0a..430060e2ff58 100644
--- a/lib/rubygems/requirement.rb
+++ b/lib/rubygems/requirement.rb
@@ -283,11 +283,11 @@ def ==(other) # :nodoc:
   protected
 
   def _sorted_requirements
-    requirements.sort_by(&:to_s)
+    @_sorted_requirements ||= requirements.sort_by(&:to_s)
   end
 
   def _tilde_requirements
-    _sorted_requirements.select {|r| r.first == "~>" }
+    @_tilde_requirements ||= _sorted_requirements.select {|r| r.first == "~>" }
   end
 
   private