diff --git a/src/libsodium/randombytes/randombytes.c b/src/libsodium/randombytes/randombytes.c
index 65c45c58..20c063ec 100644
--- a/src/libsodium/randombytes/randombytes.c
+++ b/src/libsodium/randombytes/randombytes.c
@@ -170,7 +170,7 @@ void
 randombytes_buf_deterministic(void * const buf, const size_t size,
                               const unsigned char seed[randombytes_SEEDBYTES])
 {
-    static const unsigned char zero[crypto_stream_chacha20_ietf_NONCEBYTES];
+    static const unsigned char zero[crypto_stream_chacha20_ietf_NONCEBYTES] = { 0 };
 
     COMPILER_ASSERT(randombytes_SEEDBYTES == crypto_stream_chacha20_ietf_KEYBYTES);
     if (size > 0x4000000000ULL) {