diff --git a/examples/playwave.c b/examples/playwave.c
index 3251dd33..43fe5bed 100644
--- a/examples/playwave.c
+++ b/examples/playwave.c
@@ -77,7 +77,7 @@ static void test_versions(void)
 }
 
 static int channel_is_done = 0;
-static void SDLCALL channel_complete_callback (int chan)
+static void SDLCALL channel_complete_callback (void *userdata, int chan)
 {
     if (verbose) {
         Mix_Chunk *done_chunk = Mix_GetChunk(chan);
@@ -86,6 +86,8 @@ static void SDLCALL channel_complete_callback (int chan)
         SDL_Log(" Which %s correct.\n", (g_wave == done_chunk) ? "is" : "is NOT");
     }
     channel_is_done = 1;
+
+    (void) userdata; /* rcg06192001 unused */
 }
 
 /* rcg06192001 abstract this out for testing purposes. */
@@ -415,7 +417,7 @@ int main(int argc, char *argv[])
         flip_sample(g_wave);
     }
 
-    Mix_ChannelFinished(channel_complete_callback);
+    Mix_ChannelFinished(NULL, channel_complete_callback);
 
     if ((!Mix_SetReverseStereo(MIX_CHANNEL_POST, reverse_stereo)) &&
          (reverse_stereo))
diff --git a/include/SDL3_mixer/SDL_mixer.h b/include/SDL3_mixer/SDL_mixer.h
index b912882e..3db1d078 100644
--- a/include/SDL3_mixer/SDL_mixer.h
+++ b/include/SDL3_mixer/SDL_mixer.h
@@ -1052,7 +1052,7 @@ extern SDL_DECLSPEC void SDLCALL Mix_HookMusicFinished(Mix_MusicFinishedCallback
  */
 extern SDL_DECLSPEC void * SDLCALL Mix_GetMusicHookData(void);
 
-typedef void (SDLCALL *Mix_ChannelFinishedCallback)(int channel);
+typedef void (SDLCALL *Mix_ChannelFinishedCallback)(void *userdata, int channel);
 
 /**
  * Set a callback that runs when a channel has finished playing.
@@ -1065,12 +1065,13 @@ typedef void (SDLCALL *Mix_ChannelFinishedCallback)(int channel);
  *
  * A NULL pointer will disable the callback.
  *
+ * \param userdata the user data to pass to the callback.
  * \param channel_finished the callback function to become the new
  *                         notification mechanism.
  *
  * \since This function is available since SDL_mixer 3.0.0.
  */
-extern SDL_DECLSPEC void SDLCALL Mix_ChannelFinished(Mix_ChannelFinishedCallback channel_finished);
+extern SDL_DECLSPEC void SDLCALL Mix_ChannelFinished(void *userdata, Mix_ChannelFinishedCallback channel_finished);
 
 /**
  * Magic number for effects to operate on the postmix instead of a channel.
diff --git a/src/mixer.c b/src/mixer.c
index 6f548e3f..ddfdd178 100644
--- a/src/mixer.c
+++ b/src/mixer.c
@@ -100,6 +100,7 @@ static void *mix_postmix_data = NULL;
 
 /* rcg07062001 callback to alert when channels are done playing. */
 static Mix_ChannelFinishedCallback channel_done_callback = NULL;
+static void *channel_done_callback_userdata = NULL;
 
 /* Support for user defined music functions */
 static Mix_MixCallback mix_music = music_mixer;
@@ -291,7 +292,7 @@ static bool _Mix_remove_all_effects(int channel, effect_info **e);
 static void _Mix_channel_done_playing(int channel)
 {
     if (channel_done_callback) {
-        channel_done_callback(channel);
+        channel_done_callback(channel_done_callback_userdata, channel);
     }
 
     /*
@@ -1023,10 +1024,11 @@ void *Mix_GetMusicHookData(void)
     return music_data;
 }
 
-void Mix_ChannelFinished(Mix_ChannelFinishedCallback channel_finished)
+void Mix_ChannelFinished(void *userdata, Mix_ChannelFinishedCallback channel_finished)
 {
     Mix_LockAudio();
     channel_done_callback = channel_finished;
+    channel_done_callback_userdata = userdata;
     Mix_UnlockAudio();
 }