diff --git a/README.md b/README.md
index 66a0057..53c6f6d 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,7 @@ Idea by: https://ruby-china.org/topics/20558#reply4
 
 ## Requirements
 
-- ImageMagick 6.9+
+- ImageMagick
 
 #### Ubuntu
 
@@ -55,8 +55,8 @@ Create `config/initializers/rucaptcha.rb`
 RuCaptcha.configure do
   # Number of chars, default: 4
   self.len = 4
-  # Image font size, default: 48
-  self.font_size = 48
+  # Image font size, default: 45
+  self.font_size = 45
   # Cache generated images in file store, this is config files limit, default: 100
   # set 0 to disable file cache.
   self.cache_limit = 100
diff --git a/lib/rucaptcha/configuration.rb b/lib/rucaptcha/configuration.rb
index 6fea8d3..2c502e4 100644
--- a/lib/rucaptcha/configuration.rb
+++ b/lib/rucaptcha/configuration.rb
@@ -2,7 +2,7 @@ module RuCaptcha
   class Configuration
     # TODO: remove height, width in 0.3.0
     attr_accessor :height, :width
-    # Image font size, default 48
+    # Image font size, default 45
     attr_accessor :font_size
     # Number of chars, default 4
     attr_accessor :len