diff --git a/c_src/enacl_nif.c b/c_src/enacl_nif.c
index 29862c3..5b1cf58 100644
--- a/c_src/enacl_nif.c
+++ b/c_src/enacl_nif.c
@@ -1167,7 +1167,7 @@ void uint64_pack(unsigned char *y, ErlNifUInt64 x)
 	*y++ = x; x >>= 8;
 	*y++ = x; x >>= 8;
 	*y++ = x; x >>= 8;
-	*y++ = x; x >>= 8;
+	*y++ = x;
 }
 
 static