diff --git a/lib/masamune/schema/column.rb b/lib/masamune/schema/column.rb
index 1c17e4e..05e1ac9 100644
--- a/lib/masamune/schema/column.rb
+++ b/lib/masamune/schema/column.rb
@@ -243,7 +243,7 @@ def ruby_value(value, recursive = true)
         when Date, DateTime
           value.to_time
         when String
-          if value =~ /^\d+$/
+          if value =~ /\A\d+\z/
             Time.at(value.to_i)
           else
             Time.parse(value)