diff --git a/kernel/common/marshal.rb b/kernel/common/marshal.rb
index 4f27d7ad52..66fe2ac25b 100644
--- a/kernel/common/marshal.rb
+++ b/kernel/common/marshal.rb
@@ -79,28 +79,13 @@ def __marshal__(ms)
 
 class Fixnum
   def __marshal__(ms)
-    "i#{ms.serialize_integer(self)}"
+    ms.serialize_integer(self, "i")
   end
 end
 
 class Bignum
   def __marshal__(ms)
-    str = (self < 0 ? 'l-' : 'l+')
-    cnt = 0
-    num = self.abs
-
-    while num != 0
-      str << (num & 0xff).chr
-      num >>= 8
-      cnt += 1
-    end
-
-    if cnt % 2 == 1
-      str << "\0"
-      cnt += 1
-    end
-
-    str[0..1] + ms.serialize_integer(cnt / 2) + str[2..-1]
+    ms.serialize_bignum(self)
   end
 end
 
@@ -799,7 +784,19 @@ def serialize_instance_variables_suffix(obj, force=false,
       end
     end
 
-    def serialize_integer(n)
+    def serialize_integer(n, prefix = nil)
+      if !Rubinius::L64 && n.is_a?(Fixnum)
+        prefix.to_s + serialize_fixnum(n)
+      else
+        if (n >> 31) == 0 or (n >> 31) == -1
+          prefix.to_s + serialize_fixnum(n)
+        else
+          serialize_bignum(n)
+        end
+      end
+    end
+
+    def serialize_fixnum(n)
       if n == 0
         s = n.chr
       elsif n > 0 and n < 123
@@ -820,6 +817,25 @@ def serialize_integer(n)
       s
     end
 
+    def serialize_bignum(n)
+      str = (n < 0 ? 'l-' : 'l+')
+      cnt = 0
+      num = n.abs
+ 
+      while num != 0
+        str << (num & 0xff).chr
+        num >>= 8
+        cnt += 1
+      end
+ 
+      if cnt % 2 == 1
+        str << "\0"
+        cnt += 1
+      end
+ 
+      str[0..1] + serialize_fixnum(cnt / 2) + str[2..-1]
+    end
+
     def serialize_user_class(obj, cls)
       if obj.class != cls
         "C#{serialize(obj.class.name.to_sym)}"