diff --git a/include/linux/lz4.h b/include/linux/lz4.h
index d21c13f..4356686 100644
--- a/include/linux/lz4.h
+++ b/include/linux/lz4.h
@@ -67,8 +67,8 @@
  *	note :  Destination buffer must be already allocated.
  *		slightly faster than lz4_decompress_unknownoutputsize()
  */
-int lz4_decompress(const char *src, size_t *src_len, char *dest,
-		size_t actual_dest_len);
+int lz4_decompress(const unsigned char *src, size_t *src_len,
+		unsigned char *dest, size_t actual_dest_len);
 
 /*
  * lz4_decompress_unknownoutputsize()
@@ -82,6 +82,6 @@
  *		  Error if return (< 0)
  *	note :  Destination buffer must be already allocated.
  */
-int lz4_decompress_unknownoutputsize(const char *src, size_t src_len,
-		char *dest, size_t *dest_len);
+int lz4_decompress_unknownoutputsize(const unsigned char *src, size_t src_len,
+		unsigned char *dest, size_t *dest_len);
 #endif