cmd/zstd/enzstd.c | 4 ++--

diff --git a/cmd/zstd/enzstd.c b/cmd/zstd/enzstd.c
index b67d6099a613dedf5db0cb7e44283abf8c29b254ec51af983b1248fcdc24f161..d40e47e6fdd4aad64e111ba892e2f6e62a3c85bb9ff34278e0cb3f767998efc6 100644
--- a/cmd/zstd/enzstd.c
+++ b/cmd/zstd/enzstd.c
@@ -47,8 +47,8 @@         fprintf(stderr, "can not setParameter: %s\n", ZSTD_getErrorName(zCode));
         return EXIT_FAILURE;
     }
 
-    char *src = NULL;
-    char *dst = NULL;
+    unsigned char *src = NULL;
+    unsigned char *dst = NULL;
     int rc = EXIT_FAILURE;
     size_t srcSize = 8;
     src = malloc(srcSize);