diff --git a/mrbgems/mruby-numeric-ext/mrblib/numeric_ext.rb b/mrbgems/mruby-numeric-ext/mrblib/numeric_ext.rb
index 0bf3c6ab6..f250538fe 100644
--- a/mrbgems/mruby-numeric-ext/mrblib/numeric_ext.rb
+++ b/mrbgems/mruby-numeric-ext/mrblib/numeric_ext.rb
@@ -14,4 +14,12 @@ module Integral
       self
     end
   end
+
+  def positive?
+    self > 0
+  end
+
+  def negative?
+    self < 0
+  end
 end