diff --git a/ChangeLog b/ChangeLog
index 248540a1dc..2167026ee3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Jan 17 10:48:56 2013  Aaron Patterson <aaron@tenderlovemaking.com>
+
+	* ext/psych/lib/psych/scalar_scanner.rb: use constants rather than
+	  calculating Inf and NaN.
+
 Thu Jan 17 10:21:05 2013  Eric Hodel  <drbrain@segment7.net>
 
 	* doc/syntax/miscellaneous.rdoc:  Added Ending an Expression and
diff --git a/ext/psych/lib/psych/scalar_scanner.rb b/ext/psych/lib/psych/scalar_scanner.rb
index 575945990f..8aa594e333 100644
--- a/ext/psych/lib/psych/scalar_scanner.rb
+++ b/ext/psych/lib/psych/scalar_scanner.rb
@@ -68,11 +68,11 @@ module Psych
           string
         end
       when /^\.inf$/i
-        1 / 0.0
+        Float::INFINITY
       when /^-\.inf$/i
-        -1 / 0.0
+        -Float::INFINITY
       when /^\.nan$/i
-        0.0 / 0.0
+        Float::NAN
       when /^:./
         if string =~ /^:(["'])(.*)\1/
           @symbol_cache[string] = $2.sub(/^:/, '').to_sym