diff --git a/src/libs/blake2.h b/src/libs/blake2.h
index ca39030..a51262c 100644
--- a/src/libs/blake2.h
+++ b/src/libs/blake2.h
@@ -18,7 +18,9 @@
 #include <stddef.h>
 #include <stdint.h>
 
-#if defined(_MSC_VER)
+#if defined(WATCOM)
+#define BLAKE2_PACKED(x) _Packed x
+#elif defined(_MSC_VER)
 #define BLAKE2_PACKED(x) __pragma(pack(push, 1)) x __pragma(pack(pop))
 #else
 #define BLAKE2_PACKED(x) x __attribute__((packed))