diff --git a/player/client.c b/player/client.c
index 8e2bc4d1b7..6a8204615f 100644
--- a/player/client.c
+++ b/player/client.c
@@ -620,7 +620,7 @@ int mpv_request_event(mpv_handle *ctx, mpv_event_id event, int enable)
 {
     if (!mpv_event_name(event) || enable < 0 || enable > 1)
         return MPV_ERROR_INVALID_PARAMETER;
-    assert(event < INTERNAL_EVENT_BASE); // excluded above; they have no name
+    assert(event < (int)INTERNAL_EVENT_BASE); // excluded above; they have no name
     pthread_mutex_lock(&ctx->lock);
     uint64_t bit = 1ULL << event;
     ctx->event_mask = enable ? ctx->event_mask | bit : ctx->event_mask & ~bit;
diff --git a/player/command.c b/player/command.c
index aa44196925..391cc5b30a 100644
--- a/player/command.c
+++ b/player/command.c
@@ -3201,6 +3201,7 @@ static const char *const *const mp_event_property_change[] = {
     E(MPV_EVENT_CHAPTER_CHANGE, "chapter", "chapter-metadata"),
     E(MP_EVENT_CACHE_UPDATE, "cache", "cache-free", "cache-used", "cache-idle",
       "demuxer-cache-duration", "demuxer-cache-idle"),
+    E(MP_EVENT_WIN_RESIZE, "window-scale"),
 };
 #undef E
 
diff --git a/player/command.h b/player/command.h
index 0307bd06b7..3469e32948 100644
--- a/player/command.h
+++ b/player/command.h
@@ -39,9 +39,13 @@ void mp_notify_property(struct MPContext *mpctx, const char *property);
 int mp_get_property_id(const char *name);
 uint64_t mp_get_property_event_mask(const char *name);
 
-// Must start with the first unused positive value in enum mpv_event_id
-#define INTERNAL_EVENT_BASE 24
-#define MP_EVENT_CACHE_UPDATE (INTERNAL_EVENT_BASE + 0)
+enum {
+    // Must start with the first unused positive value in enum mpv_event_id
+    // MPV_EVENT_* and MP_EVENT_* must not overlap.
+    INTERNAL_EVENT_BASE = 24,
+    MP_EVENT_CACHE_UPDATE,
+    MP_EVENT_WIN_RESIZE,
+};
 
 bool mp_hook_test_completion(struct MPContext *mpctx, char *type);
 void mp_hook_run(struct MPContext *mpctx, char *client, char *type);
diff --git a/player/playloop.c b/player/playloop.c
index 22cc12f70d..85d962fffe 100644
--- a/player/playloop.c
+++ b/player/playloop.c
@@ -670,6 +670,14 @@ static void handle_cursor_autohide(struct MPContext *mpctx)
     mpctx->mouse_cursor_visible = mouse_cursor_visible;
 }
 
+static void handle_vo_events(struct MPContext *mpctx)
+{
+    struct vo *vo = mpctx->video_out;
+    int events = vo ? vo_query_events(vo, VO_EVENTS_USER, true) : 0;
+    if (events & VO_EVENT_RESIZE)
+        mp_notify(mpctx, MP_EVENT_WIN_RESIZE, NULL);
+}
+
 void add_frame_pts(struct MPContext *mpctx, double pts)
 {
     if (pts == MP_NOPTS_VALUE || mpctx->hrseek_framedrop) {
@@ -884,6 +892,7 @@ void run_playloop(struct MPContext *mpctx)
     }
 
     handle_cursor_autohide(mpctx);
+    handle_vo_events(mpctx);
     handle_heartbeat_cmd(mpctx);
 
     fill_audio_out_buffers(mpctx, endpts);
@@ -995,6 +1004,7 @@ void mp_idle(struct MPContext *mpctx)
     mpctx->sleeptime = 100.0;
     mp_process_input(mpctx);
     handle_cursor_autohide(mpctx);
+    handle_vo_events(mpctx);
     update_osd_msg(mpctx);
     handle_osd_redraw(mpctx);
 }
diff --git a/video/out/vo.c b/video/out/vo.c
index 9f6021282f..f697002f92 100644
--- a/video/out/vo.c
+++ b/video/out/vo.c
@@ -129,6 +129,7 @@ struct vo_internal {
     bool request_redraw;            // redraw request from player to VO
     bool want_redraw;               // redraw request from VO to player
     bool paused;
+    int queued_events;
 
     int64_t flip_queue_offset; // queue flip events at most this much in advance
 
@@ -838,6 +839,31 @@ int64_t vo_get_vsync_interval(struct vo *vo)
     return vo->in->vsync_interval;
 }
 
+// Set specific event flags, and wakeup the playback core if needed.
+// vo_query_events() can retrieve the events again.
+void vo_event(struct vo *vo, int event)
+{
+    struct vo_internal *in = vo->in;
+    pthread_mutex_lock(&in->lock);
+    if ((in->queued_events & event & VO_EVENTS_USER) != (event & VO_EVENTS_USER))
+        mp_input_wakeup(vo->input_ctx);
+    in->queued_events |= event;
+    pthread_mutex_unlock(&in->lock);
+}
+
+// Check event flags set with vo_event(). Return the mask of events that was
+// set and included in the events parameter. If clear==true, clear these events.
+int vo_query_events(struct vo *vo, int events, bool clear)
+{
+    struct vo_internal *in = vo->in;
+    pthread_mutex_lock(&in->lock);
+    int r = in->queued_events & events;
+    if (clear)
+        in->queued_events &= ~(unsigned)r;
+    pthread_mutex_unlock(&in->lock);
+    return r;
+}
+
 /**
  * \brief lookup an integer in a table, table must have 0 as the last key
  * \param key key to search for
diff --git a/video/out/vo.h b/video/out/vo.h
index feb2907c67..035b4dc1d6 100644
--- a/video/out/vo.h
+++ b/video/out/vo.h
@@ -30,10 +30,16 @@
 #include "common/common.h"
 #include "options/options.h"
 
+// VO needs to redraw
 #define VO_EVENT_EXPOSE 1
+// VO needs to update state to a new window size
 #define VO_EVENT_RESIZE 2
+// The ICC profile needs to be reloaded
 #define VO_EVENT_ICC_PROFILE_PATH_CHANGED 4
 
+// Set of events the player core may be interested in.
+#define VO_EVENTS_USER (VO_EVENT_RESIZE)
+
 enum mp_voctrl {
     /* signal a device reset seek */
     VOCTRL_RESET = 1,
@@ -298,6 +304,8 @@ void vo_destroy(struct vo *vo);
 void vo_set_paused(struct vo *vo, bool paused);
 int64_t vo_get_drop_count(struct vo *vo);
 int vo_query_format(struct vo *vo, int format);
+void vo_event(struct vo *vo, int event);
+int vo_query_events(struct vo *vo, int events, bool clear);
 
 void vo_set_flip_queue_offset(struct vo *vo, int64_t us);
 int64_t vo_get_vsync_interval(struct vo *vo);
diff --git a/video/out/vo_direct3d.c b/video/out/vo_direct3d.c
index 4b81026e35..88575c4e7a 100644
--- a/video/out/vo_direct3d.c
+++ b/video/out/vo_direct3d.c
@@ -1267,6 +1267,8 @@ static int control(struct vo *vo, uint32_t request, void *data)
     if (events & VO_EVENT_EXPOSE)
         vo->want_redraw = true;
 
+    vo_event(vo, events);
+
     return r;
 }
 
diff --git a/video/out/vo_opengl.c b/video/out/vo_opengl.c
index 3b6e3a2e43..4e1b1a53ea 100644
--- a/video/out/vo_opengl.c
+++ b/video/out/vo_opengl.c
@@ -439,6 +439,7 @@ static int control(struct vo *vo, uint32_t request, void *data)
         get_and_update_icc_profile(vo, p->icc_opts);
         vo->want_redraw = true;
     }
+    vo_event(vo, events);
     mpgl_unlock(p->glctx);
 
     return r;
diff --git a/video/out/vo_opengl_old.c b/video/out/vo_opengl_old.c
index 87ba48068a..91a14398d5 100644
--- a/video/out/vo_opengl_old.c
+++ b/video/out/vo_opengl_old.c
@@ -2161,6 +2161,7 @@ static int control(struct vo *vo, uint32_t request, void *data)
         resize(vo, vo->dwidth, vo->dheight);
     if (events & VO_EVENT_EXPOSE)
         vo->want_redraw = true;
+    vo_event(vo, events);
 
     return r;
 }
diff --git a/video/out/vo_sdl.c b/video/out/vo_sdl.c
index c904793ca0..822b5009aa 100644
--- a/video/out/vo_sdl.c
+++ b/video/out/vo_sdl.c
@@ -561,6 +561,7 @@ static int wait_events(struct vo *vo, int64_t until_time_us)
                 break;
             case SDL_WINDOWEVENT_SIZE_CHANGED:
                 check_resize(vo);
+                vo_event(vo, VO_EVENT_RESIZE);
                 break;
             }
             break;
diff --git a/video/out/vo_vaapi.c b/video/out/vo_vaapi.c
index fa23c931c6..89e22d8bbf 100644
--- a/video/out/vo_vaapi.c
+++ b/video/out/vo_vaapi.c
@@ -567,6 +567,7 @@ static int control(struct vo *vo, uint32_t request, void *data)
         resize(p);
     if (events & VO_EVENT_EXPOSE)
         vo->want_redraw = true;
+    vo_event(vo, events);
     return r;
 }
 
diff --git a/video/out/vo_vdpau.c b/video/out/vo_vdpau.c
index c8836a8639..46190fd032 100644
--- a/video/out/vo_vdpau.c
+++ b/video/out/vo_vdpau.c
@@ -1114,6 +1114,7 @@ static int control(struct vo *vo, uint32_t request, void *data)
     } else if (events & VO_EVENT_EXPOSE) {
         vo->want_redraw = true;
     }
+    vo_event(vo, events);
 
     return r;
 }
diff --git a/video/out/vo_wayland.c b/video/out/vo_wayland.c
index ac6c561526..87e38e45b3 100644
--- a/video/out/vo_wayland.c
+++ b/video/out/vo_wayland.c
@@ -705,6 +705,8 @@ static int control(struct vo *vo, uint32_t request, void *data)
     if (events & VO_EVENT_RESIZE)
         resize(p);
 
+    vo_event(vo, events);
+
     return r;
 }
 
diff --git a/video/out/vo_x11.c b/video/out/vo_x11.c
index 914522e6b8..38a60c1be8 100644
--- a/video/out/vo_x11.c
+++ b/video/out/vo_x11.c
@@ -631,6 +631,7 @@ static int control(struct vo *vo, uint32_t request, void *data)
     int r = vo_x11_control(vo, &events, request, data);
     if (events & (VO_EVENT_EXPOSE | VO_EVENT_RESIZE))
         resize(vo);
+    vo_event(vo, events);
     return r;
 }
 
diff --git a/video/out/vo_xv.c b/video/out/vo_xv.c
index 1ea16558ac..07495fb89e 100644
--- a/video/out/vo_xv.c
+++ b/video/out/vo_xv.c
@@ -851,6 +851,7 @@ static int control(struct vo *vo, uint32_t request, void *data)
     int r = vo_x11_control(vo, &events, request, data);
     if (events & (VO_EVENT_EXPOSE | VO_EVENT_RESIZE))
         resize(vo);
+    vo_event(vo, events);
     return r;
 }