diff --git a/lib/mysql2/aws_iam_auth.rb b/lib/mysql2/aws_iam_auth.rb
index 03a56538..df1ac01e 100644
--- a/lib/mysql2/aws_iam_auth.rb
+++ b/lib/mysql2/aws_iam_auth.rb
@@ -6,7 +6,7 @@ class AwsTokenAuth
 
     # Tokens are valid for up to 15 minutes.
     # We will assume ours expire in 14 minutes to be safe.
-    TOKEN_EXPIRES_IN = (60*14) # 14 minutes
+    TOKEN_EXPIRES_IN = (60 * 14) # 14 minutes
 
     def initialize
       begin
@@ -25,7 +25,7 @@ def initialize
       @generator = Aws::RDS::AuthTokenGenerator.new
     end
 
-    def password(user, host port, opts)
+    def password(user, host, port, opts)
       params = to_params(user, host, port, opts)
       key = key_from_params(params)
       passwd = nil
@@ -35,9 +35,10 @@ def password(user, host port, opts)
             passwd = @passwords[key][:password]
           end
         rescue KeyError
+          passwd = nil
         end
       end
-      if passwd return passwd
+      return passwd unless passwd.nil?
 
       AwsTokenAuth.instance.mutex.synchronize do
         @passwords[key] = {}
@@ -59,8 +60,7 @@ def to_params(user, host, port, opts)
     end
 
     def key_from_params(params)
-      return "#{params[:user_name]}/#{params[:endpoint]}/#{params[:region]}"
+      "#{params[:user_name]}/#{params[:endpoint]}/#{params[:region]}"
     end
-
   end
 end