diff --git a/CHANGES b/CHANGES
index 3e69f3a..da07bd9 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,9 @@
 i2c-tools CHANGES
 -----------------
 
+SVN
+  i2c-dev.h: Make value arrays const for block write functions
+
 3.0.3 (2010-12-12)
   Makefile: Let the environment set CC and CFLAGS
             Integrate py-smbus into the build system
diff --git a/include/linux/i2c-dev.h b/include/linux/i2c-dev.h
index 15db8b0..fb9b20a 100644
--- a/include/linux/i2c-dev.h
+++ b/include/linux/i2c-dev.h
@@ -258,7 +258,7 @@ static inline __s32 i2c_smbus_read_block_data(int file, __u8 command,
 }
 
 static inline __s32 i2c_smbus_write_block_data(int file, __u8 command, 
-                                               __u8 length, __u8 *values)
+                                               __u8 length, const __u8 *values)
 {
 	union i2c_smbus_data data;
 	int i;
@@ -296,7 +296,8 @@ static inline __s32 i2c_smbus_read_i2c_block_data(int file, __u8 command,
 }
 
 static inline __s32 i2c_smbus_write_i2c_block_data(int file, __u8 command,
-                                               __u8 length, __u8 *values)
+                                                   __u8 length,
+                                                   const __u8 *values)
 {
 	union i2c_smbus_data data;
 	int i;