diff --git a/src/osgPlugins/ive/ReadWrite.h b/src/osgPlugins/ive/ReadWrite.h
index a70ee580b..586bfb01b 100644
--- a/src/osgPlugins/ive/ReadWrite.h
+++ b/src/osgPlugins/ive/ReadWrite.h
@@ -183,8 +183,8 @@ class ReadWrite{
 
 public:
     virtual ~ReadWrite() {}
-    virtual void write(DataOutputStream* out) const = 0;
-    virtual void read(DataInputStream* out) const = 0;
+    virtual void write(DataOutputStream* out) = 0;
+    virtual void read(DataInputStream* out) = 0;
 };
 
 }