diff --git a/lib/nexpose/rexlite/mime/header.rb b/lib/nexpose/rexlite/mime/header.rb
index 709fd60f..d9f33bad 100644
--- a/lib/nexpose/rexlite/mime/header.rb
+++ b/lib/nexpose/rexlite/mime/header.rb
@@ -36,7 +36,7 @@ def to_s
       end
 
       def find(idx)
-        if (idx.class == ::Fixnum)
+        if idx.kind_of?(Integer)
           return self.headers[idx]
         else
           self.headers.each do |pair|
@@ -59,7 +59,7 @@ def add(var, val)
       end
 
       def remove(idx)
-        if (idx.class == ::Fixnum)
+        if idx.kind_of?(Integer)
           self.headers.delete_at(idx)
         else
           self.headers.each_index do |i|