1 files changed, 1 insertions, 1 deletions
diff --git a/lib/cgi-lib.rb b/lib/cgi-lib.rb
index 362d13f8d0..1a6d16a6da 100644
--- a/lib/cgi-lib.rb
+++ b/lib/cgi-lib.rb
@@ -81,7 +81,7 @@ class CGI < SimpleDelegator
   end
 
   def CGI.error
-    m = $!.dup
+    m = $!.to_s.dup
     m.gsub!(/&/, '&amp;')
     m.gsub!(/</, '&lt;')
     m.gsub!(/>/, '&gt;')