diff --git a/lib/i18nliner/base.rb b/lib/i18nliner/base.rb
index <HASH>..<HASH> 100644
--- a/lib/i18nliner/base.rb
+++ b/lib/i18nliner/base.rb
@@ -45,4 +45,5 @@ module I18nliner
   setting :inferred_key_format,        :underscored_crc32
   setting :infer_interpolation_values, true
   setting :base_path,                  "./"
+  setting :underscored_key_length,     50
 end
diff --git a/lib/i18nliner/call_helpers.rb b/lib/i18nliner/call_helpers.rb
index <HASH>..<HASH> 100644
--- a/lib/i18nliner/call_helpers.rb
+++ b/lib/i18nliner/call_helpers.rb
@@ -35,7 +35,7 @@ module I18nliner
       key.downcase!
       key.gsub!(/[^a-z0-9_]+/, '_')
       key.gsub!(/\A_|_\z/, '')
-      key[0..50]
+      key[0...I18nliner.underscored_key_length]
     end
 
     def keyify_underscored_crc32(string)
configurable underscored key length (now <I> instead of <I>), fixes #3