diff --git a/lib/testers/base.rb b/lib/testers/base.rb
index c541d82..a0cb3d3 100644
--- a/lib/testers/base.rb
+++ b/lib/testers/base.rb
@@ -2,7 +2,7 @@ class Wait
   class BaseTester
     attr_accessor :logger
 
-    # Returns +true+ if a result if valid.
+    # Returns +true+ if a result is valid.
     def valid?(result)
       log(result)