diff --git a/lib/prime.rb b/lib/prime.rb
index 86db1957a3..2cd22da3a8 100644
--- a/lib/prime.rb
+++ b/lib/prime.rb
@@ -419,7 +419,7 @@ class Prime
     end
   end
 
-  # Internal use. An implementation of eratosthenes' sieve
+  # Internal use. An implementation of Eratosthenes' sieve
   class EratosthenesSieve
     include Singleton
 
diff --git a/test/test_prime.rb b/test/test_prime.rb
index fe847eb832..7ff07eeb6a 100644
--- a/test/test_prime.rb
+++ b/test/test_prime.rb
@@ -189,6 +189,7 @@ class TestPrime < Test::Unit::TestCase
     ensure
       class << Integer
         alias_method :sqrt, :org_sqrt
+        remove_method :org_sqrt
       end
     end