diff --git a/ha_ibmdb2i.cc b/ha_ibmdb2i.cc
index 41ee101..499a1b3 100644
--- a/ha_ibmdb2i.cc
+++ b/ha_ibmdb2i.cc
@@ -896,7 +896,7 @@ int ha_ibmdb2i::prepareRowForWrite(char* data, char* nulls, bool honorIdentCols)
 
 
 
-int ha_ibmdb2i::update_row(const uchar * old_data, uchar * new_data)
+int ha_ibmdb2i::update_row(const uchar * old_data, const uchar * new_data)
 {
   DBUG_ENTER("ha_ibmdb2i::update_row");
   increment_statistics(&SSV::ha_update_count);
diff --git a/ha_ibmdb2i.h b/ha_ibmdb2i.h
index 9eeb8d5..e6ce96a 100644
--- a/ha_ibmdb2i.h
+++ b/ha_ibmdb2i.h
@@ -243,7 +243,7 @@ class ha_ibmdb2i: public handler
   int open(const char *name, int mode, uint test_if_locked);
   int close(void);
   int write_row(uchar * buf);
-  int update_row(const uchar * old_data, uchar * new_data);
+  virtual int update_row(const uchar * old_data, const uchar * new_data) override;
   int delete_row(const uchar * buf);
   int index_init(uint idx, bool sorted);
   int index_read(uchar * buf, const uchar * key,