diff --git a/src/crypto/c_threads.h b/src/crypto/c_threads.h
index b4f7736415c..3457738b38f 100644
--- a/src/crypto/c_threads.h
+++ b/src/crypto/c_threads.h
@@ -42,10 +42,11 @@
 #define CTHR_RWLOCK_TRYLOCK_READ(x)	TryAcquireSRWLockShared(&x)
 
 #define CTHR_THREAD_TYPE	HANDLE
-#define CTHR_THREAD_RTYPE	void
-#define CTHR_THREAD_RETURN	return
-#define CTHR_THREAD_CREATE(thr, func, arg)	((thr = (HANDLE)_beginthread(func, 0, arg)) != -1L)
-#define CTHR_THREAD_JOIN(thr)			WaitForSingleObject((HANDLE)thr, INFINITE)
+#define CTHR_THREAD_RTYPE	unsigned __stdcall
+#define CTHR_THREAD_RETURN	_endthreadex(0); return 0;
+#define CTHR_THREAD_CREATE(thr, func, arg)	((thr = (HANDLE)_beginthreadex(0, 0, func, arg, 0, 0)) != 0L)
+#define CTHR_THREAD_JOIN(thr)			do { WaitForSingleObject(thr, INFINITE); CloseHandle(thr); } while(0)
+#define CTHR_THREAD_CLOSE(thr)			CloseHandle((HANDLE)thr);
 
 #else
 
@@ -64,5 +65,6 @@
 #define CTHR_THREAD_RETURN	return NULL
 #define CTHR_THREAD_CREATE(thr, func, arg)	(pthread_create(&thr, NULL, func, arg) == 0)
 #define CTHR_THREAD_JOIN(thr)			pthread_join(thr, NULL)
+#define CTHR_THREAD_CLOSE(thr)
 
 #endif
diff --git a/src/crypto/rx-slow-hash.c b/src/crypto/rx-slow-hash.c
index 14fb56e07bd..672144fcfcf 100644
--- a/src/crypto/rx-slow-hash.c
+++ b/src/crypto/rx-slow-hash.c
@@ -332,7 +332,7 @@ static void rx_init_dataset(size_t max_threads) {
       local_abort("Couldn't start RandomX seed thread");
     }
   }
-  rx_seedthread(&si[n1]);
+  randomx_init_dataset(main_dataset, si[n1].si_cache, si[n1].si_start, si[n1].si_count);
   for (size_t i = 0; i < n1; ++i) CTHR_THREAD_JOIN(st[i]);
   CTHR_RWLOCK_UNLOCK_READ(main_cache_lock);
 
@@ -402,6 +402,7 @@ void rx_set_main_seedhash(const char *seedhash, size_t max_dataset_init_threads)
   if (!CTHR_THREAD_CREATE(t, rx_set_main_seedhash_thread, info)) {
     local_abort("Couldn't start RandomX seed thread");
   }
+  CTHR_THREAD_CLOSE(t);
 }
 
 void rx_slow_hash(const char *seedhash, const void *data, size_t length, char *result_hash) {