diff --git a/fenster_audio.h b/fenster_audio.h
index f9598ec..e4451bb 100644
--- a/fenster_audio.h
+++ b/fenster_audio.h
@@ -19,7 +19,14 @@ struct fenster_audio {
   dispatch_semaphore_t full;
 };
 #elif defined(_WIN32)
-struct fenster_audio {};
+#include <mmsystem.h>
+#include <windows.h>
+struct fenster_audio {
+  WAVEHDR header;
+  HWAVEOUT wo;
+  WAVEHDR hdr[2];
+  char buf[2][FENSTER_AUDIO_BUFSZ];
+};
 #elif defined(__linux__)
 struct fenster_audio {
   void *pcm;
@@ -87,11 +94,39 @@ FENSTER_API void fenster_audio_write(struct fenster_audio *fa, float *buf,
 }
 #elif defined(_WIN32)
 /* TODO */
-FENSTER_API int fenster_audio_open(struct fenster_audio *f) { return -1; }
-FENSTER_API int fenster_audio_available(struct fenster_audio *f) { return -1; }
-FENSTER_API void fenster_audio_write(struct fenster_audio *f, float *buf,
-                                     size_t n) {}
-FENSTER_API void fenster_audio_close(struct fenster_audio *f) {}
+FENSTER_API int fenster_audio_open(struct fenster_audio *fa) {
+  WAVEFORMATEX wfx = {
+      WAVE_FORMAT_PCM, 1, FENSTER_SAMPLE_RATE, FENSTER_SAMPLE_RATE, 1, 8, 0};
+  waveOutOpen(&fa->wo, WAVE_MAPPER, &wfx, 0, 0, CALLBACK_NULL);
+  for (int i = 0; i < 2; i++) {
+    fa->hdr[i].lpData = fa->buf[i];
+    fa->hdr[i].dwBufferLength = FENSTER_AUDIO_BUFSZ;
+    waveOutPrepareHeader(fa->wo, &fa->hdr[i], sizeof(WAVEHDR));
+    waveOutWrite(fa->wo, &fa->hdr[i], sizeof(WAVEHDR));
+  }
+  return 0;
+}
+FENSTER_API int fenster_audio_available(struct fenster_audio *fa) {
+  for (int i = 0; i < 2; i++)
+    if (fa->hdr[i].dwFlags & WHDR_DONE)
+      return FENSTER_AUDIO_BUFSZ;
+  return 0;
+}
+FENSTER_API void fenster_audio_write(struct fenster_audio *fa, float *buf,
+                                     size_t n) {
+  for (int i = 0; i < 2; i++) {
+    if (fa->hdr[i].dwFlags & WHDR_DONE) {
+      for (unsigned j = 0; j < n; j++) {
+        fa->buf[i][j] = (uint8_t)(buf[j] * 256);
+      }
+      waveOutWrite(fa->wo, &fa->hdr[i], sizeof(WAVEHDR));
+      return;
+    }
+  }
+}
+FENSTER_API void fenster_audio_close(struct fenster_audio *fa) {
+  waveOutClose(fa->wo);
+}
 #elif defined(__linux__)
 int snd_pcm_open(void **, const char *, int, int);
 int snd_pcm_set_params(void *, int, int, int, int, int, int);