diff --git a/coreapi/linphonecall.c b/coreapi/linphonecall.c
index 6cee394d7..94ebefcaf 100644
--- a/coreapi/linphonecall.c
+++ b/coreapi/linphonecall.c
@@ -2744,12 +2744,12 @@ static void linphone_call_start_video_stream(LinphoneCall *call, bool_t all_inpu
 			video_stream_set_fps(call->videostream,linphone_core_get_preferred_framerate(lc));
 			video_stream_set_sent_video_size(call->videostream,linphone_core_get_preferred_video_size(lc));
 			video_stream_enable_self_view(call->videostream,lc->video_conf.selfview);
-			if (call->video_window_id != 0)
-				video_stream_set_native_window_id(call->videostream,call->video_window_id);
-			else if (lc->video_window_id!=0)
-				video_stream_set_native_window_id(call->videostream,lc->video_window_id);
-			if (lc->preview_window_id!=0)
-				video_stream_set_native_preview_window_id (call->videostream,lc->preview_window_id);
+			if (call->video_window_id != NULL)
+				video_stream_set_native_window_id(call->videostream, call->video_window_id);
+			else if (lc->video_window_id != NULL)
+				video_stream_set_native_window_id(call->videostream, lc->video_window_id);
+			if (lc->preview_window_id != NULL)
+				video_stream_set_native_preview_window_id(call->videostream, lc->preview_window_id);
 			video_stream_use_preview_video_window (call->videostream,lc->use_preview_window);
 
 			if (is_multicast){
@@ -4041,7 +4041,7 @@ void linphone_call_cancel_dtmfs(LinphoneCall *call) {
 	}
 }
 
-unsigned long linphone_call_get_native_video_window_id(const LinphoneCall *call) {
+void * linphone_call_get_native_video_window_id(const LinphoneCall *call) {
 	if (call->video_window_id) {
 		/* The video id was previously set by the app. */
 		return call->video_window_id;
@@ -4055,7 +4055,7 @@ unsigned long linphone_call_get_native_video_window_id(const LinphoneCall *call)
 	return 0;
 }
 
-void linphone_call_set_native_video_window_id(LinphoneCall *call, unsigned long id) {
+void linphone_call_set_native_video_window_id(LinphoneCall *call, void *id) {
 	call->video_window_id = id;
 #ifdef VIDEO_ENABLED
 	if (call->videostream) {
diff --git a/coreapi/linphonecore.c b/coreapi/linphonecore.c
index 5a3e6d2b1..5f4a2ccf8 100644
--- a/coreapi/linphonecore.c
+++ b/coreapi/linphonecore.c
@@ -4973,7 +4973,7 @@ static void toggle_video_preview(LinphoneCore *lc, bool_t val){
 			video_preview_set_size(lc->previewstream,vsize);
 			if (display_filter)
 				video_preview_set_display_filter_name(lc->previewstream,display_filter);
-			if (lc->preview_window_id!=0)
+			if (lc->preview_window_id != NULL)
 				video_preview_set_native_window_id(lc->previewstream,lc->preview_window_id);
 			video_preview_set_fps(lc->previewstream,linphone_core_get_preferred_framerate(lc));
 			video_preview_start(lc->previewstream,lc->video_conf.device);
@@ -5273,7 +5273,7 @@ float linphone_core_get_static_picture_fps(LinphoneCore *lc) {
  *
  * @ingroup media_parameters
 **/
-unsigned long linphone_core_get_native_video_window_id(const LinphoneCore *lc){
+void * linphone_core_get_native_video_window_id(const LinphoneCore *lc){
 	if (lc->video_window_id) {
 		/* case where the video id was previously set by the app*/
 		return lc->video_window_id;
@@ -5289,13 +5289,17 @@ unsigned long linphone_core_get_native_video_window_id(const LinphoneCore *lc){
 }
 
 /* unsets the video id for all calls (indeed it may be kept by filters or videostream object itself by paused calls)*/
-static void unset_video_window_id(LinphoneCore *lc, bool_t preview, unsigned long id){
+static void unset_video_window_id(LinphoneCore *lc, bool_t preview, void *id){
 #ifdef VIDEO_ENABLED
 	LinphoneCall *call;
 	MSList *elem;
 #endif
 
-	if (id!=0 && id!=-1) {
+	if ((id != NULL)
+#ifndef _WIN32
+		&& ((unsigned long)id != (unsigned long)-1)
+#endif
+	){
 		ms_error("Invalid use of unset_video_window_id()");
 		return;
 	}
@@ -5317,8 +5321,12 @@ static void unset_video_window_id(LinphoneCore *lc, bool_t preview, unsigned lon
  * Set the native video window id where the video is to be displayed.
  * For MacOS, Linux, Windows: if not set or zero the core will create its own window, unless the special id -1 is given.
 **/
-void linphone_core_set_native_video_window_id(LinphoneCore *lc, unsigned long id){
-	if (id==0 || id==(unsigned long)-1){
+void linphone_core_set_native_video_window_id(LinphoneCore *lc, void *id){
+	if ((id == NULL)
+#ifndef _WIN32
+		|| ((unsigned long)id == (unsigned long)-1)
+#endif
+	){
 		unset_video_window_id(lc,FALSE,id);
 	}
 	lc->video_window_id=id;
@@ -5337,7 +5345,7 @@ void linphone_core_set_native_video_window_id(LinphoneCore *lc, unsigned long id
  *
  * @ingroup media_parameters
 **/
-unsigned long linphone_core_get_native_preview_window_id(const LinphoneCore *lc){
+void * linphone_core_get_native_preview_window_id(const LinphoneCore *lc){
 	if (lc->preview_window_id){
 		/*case where the id was set by the app previously*/
 		return lc->preview_window_id;
@@ -5360,8 +5368,8 @@ unsigned long linphone_core_get_native_preview_window_id(const LinphoneCore *lc)
  * This has to be used in conjonction with linphone_core_use_preview_window().
  * MacOS, Linux, Windows: if not set or zero the core will create its own window, unless the special id -1 is given.
 **/
-void linphone_core_set_native_preview_window_id(LinphoneCore *lc, unsigned long id){
-	if (id==0 || id==(unsigned long)-1){
+void linphone_core_set_native_preview_window_id(LinphoneCore *lc, void *id){
+	if (id == NULL || id==(unsigned long)-1){
 		unset_video_window_id(lc,TRUE,id);
 	}
 	lc->preview_window_id=id;
diff --git a/coreapi/linphonecore.h b/coreapi/linphonecore.h
index 54f3c2424..55f16a173 100644
--- a/coreapi/linphonecore.h
+++ b/coreapi/linphonecore.h
@@ -606,7 +606,7 @@ LINPHONE_PUBLIC void linphone_player_destroy(LinphonePlayer *obj);
  * @param window_id Id of the drawing window. Depend of video out
  * @return A pointer on the new instance. NULL if faild.
  */
-LINPHONE_PUBLIC LinphonePlayer *linphone_core_create_local_player(LinphoneCore *lc, MSSndCard *snd_card, const char *video_out, unsigned long window_id);
+LINPHONE_PUBLIC LinphonePlayer *linphone_core_create_local_player(LinphoneCore *lc, MSSndCard *snd_card, const char *video_out, void *window_id);
 
 /**
  * @brief Check whether Matroksa format is supported by the player
@@ -774,14 +774,14 @@ LINPHONE_PUBLIC	void linphone_call_cancel_dtmfs(LinphoneCall *call);
  * Get the native window handle of the video window, casted as an unsigned long.
  * @ingroup media_parameters
 **/
-LINPHONE_PUBLIC unsigned long linphone_call_get_native_video_window_id(const LinphoneCall *call);
+LINPHONE_PUBLIC void * linphone_call_get_native_video_window_id(const LinphoneCall *call);
 
 /**
  * Set the native video window id where the video is to be displayed.
  * For MacOS, Linux, Windows: if not set or 0 a window will be automatically created, unless the special id -1 is given.
  * @ingroup media_parameters
 **/
-LINPHONE_PUBLIC void linphone_call_set_native_video_window_id(LinphoneCall *call, unsigned long id);
+LINPHONE_PUBLIC void linphone_call_set_native_video_window_id(LinphoneCall *call, void * id);
 
 /**
  * Return TRUE if this call is currently part of a conference
@@ -3604,11 +3604,11 @@ LINPHONE_PUBLIC int linphone_core_set_static_picture_fps(LinphoneCore *lc, float
 LINPHONE_PUBLIC float linphone_core_get_static_picture_fps(LinphoneCore *lc);
 
 /*function to be used for eventually setting window decorations (icons, title...)*/
-LINPHONE_PUBLIC unsigned long linphone_core_get_native_video_window_id(const LinphoneCore *lc);
-LINPHONE_PUBLIC void linphone_core_set_native_video_window_id(LinphoneCore *lc, unsigned long id);
+LINPHONE_PUBLIC void * linphone_core_get_native_video_window_id(const LinphoneCore *lc);
+LINPHONE_PUBLIC void linphone_core_set_native_video_window_id(LinphoneCore *lc, void *id);
 
-LINPHONE_PUBLIC unsigned long linphone_core_get_native_preview_window_id(const LinphoneCore *lc);
-LINPHONE_PUBLIC void linphone_core_set_native_preview_window_id(LinphoneCore *lc, unsigned long id);
+LINPHONE_PUBLIC void * linphone_core_get_native_preview_window_id(const LinphoneCore *lc);
+LINPHONE_PUBLIC void linphone_core_set_native_preview_window_id(LinphoneCore *lc, void *id);
 
 /**
  * Tells the core to use a separate window for local camera preview video, instead of
diff --git a/coreapi/localplayer.c b/coreapi/localplayer.c
index 964c1c920..eb53eb640 100644
--- a/coreapi/localplayer.c
+++ b/coreapi/localplayer.c
@@ -32,7 +32,7 @@ static void _local_player_close(LinphonePlayer *obj);
 static void _local_player_destroy(LinphonePlayer *obj);
 static void _local_player_eof_callback(void *user_data);
 
-LinphonePlayer *linphone_core_create_local_player(LinphoneCore *lc, MSSndCard *snd_card, const char *video_out, unsigned long window_id) {
+LinphonePlayer *linphone_core_create_local_player(LinphoneCore *lc, MSSndCard *snd_card, const char *video_out, void *window_id) {
 	LinphonePlayer *obj = ms_new0(LinphonePlayer, 1);
 	if(snd_card == NULL) snd_card = lc->sound_conf.ring_sndcard;
 	if(video_out == NULL) video_out = linphone_core_get_video_display_filter(lc);
diff --git a/coreapi/private.h b/coreapi/private.h
index f6a3ef131..5366b9699 100644
--- a/coreapi/private.h
+++ b/coreapi/private.h
@@ -252,7 +252,7 @@ struct _LinphoneCall{
 	StunCandidate ac,vc; /*audio video ip/port discovered by STUN*/
 	struct _AudioStream *audiostream;  /**/
 	struct _VideoStream *videostream;
-	unsigned long video_window_id;
+	void *video_window_id;
 	MSAudioEndpoint *endpoint; /*used for conferencing*/
 	char *refer_to;
 	LinphoneCallParams *params;
@@ -784,8 +784,8 @@ struct _LinphoneCore
 	int audio_bw; /*IP bw consumed by audio codec, set as soon as used codec is known, its purpose is to know the remaining bw for video*/
 	LinphoneCoreWaitingCallback wait_cb;
 	void *wait_ctx;
-	unsigned long video_window_id;
-	unsigned long preview_window_id;
+	void *video_window_id;
+	void *preview_window_id;
 	time_t netup_time; /*time when network went reachable */
 	struct _EcCalibrator *ecc;
 	MSList *hooks;