diff --git a/lib/lws-plat-unix.c b/lib/lws-plat-unix.c
index c972a365..23c11b09 100644
--- a/lib/lws-plat-unix.c
+++ b/lib/lws-plat-unix.c
@@ -112,8 +112,16 @@ lws_plat_service(struct lws_context *context, int timeout_ms)
 
 	lws_libev_run(context);
 
-	context->service_tid = context->protocols[0].callback(NULL,
-				     LWS_CALLBACK_GET_THREAD_ID, NULL, NULL, 0);
+	if (!context->service_tid_detected) {
+		struct lws _lws;
+
+		memset(&_lws, 0, sizeof(_lws));
+		_lws.context = context;
+
+		context->service_tid_detected = context->protocols[0].callback(
+			&_lws, LWS_CALLBACK_GET_THREAD_ID, NULL, NULL, 0);
+	}
+	context->service_tid = context->service_tid_detected;
 
 #ifdef LWS_OPENSSL_SUPPORT
 	/* if we know we have non-network pending data, do not wait in poll */
diff --git a/lib/lws-plat-win.c b/lib/lws-plat-win.c
index ccbe47a5..eac500b2 100644
--- a/lib/lws-plat-win.c
+++ b/lib/lws-plat-win.c
@@ -149,8 +149,16 @@ lws_plat_service(struct lws_context *context, int timeout_ms)
 	if (context == NULL)
 		return 1;
 
-	context->service_tid = context->protocols[0].callback(NULL,
-				     LWS_CALLBACK_GET_THREAD_ID, NULL, NULL, 0);
+	if (!context->service_tid_detected) {
+		struct lws _lws;
+
+		memset(&_lws, 0, sizeof(_lws));
+		_lws.context = context;
+
+		context->service_tid_detected = context->protocols[0].callback(
+			&_lws, LWS_CALLBACK_GET_THREAD_ID, NULL, NULL, 0);
+	}
+	context->service_tid = context->service_tid_detected;
 
 	for (i = 0; i < context->fds_count; ++i) {
 		pfd = &context->fds[i];
diff --git a/lib/pollfd.c b/lib/pollfd.c
index 46417c8c..319abbd5 100644
--- a/lib/pollfd.c
+++ b/lib/pollfd.c
@@ -174,7 +174,7 @@ lws_change_pollfd(struct lws *wsi, int _and, int _or)
 
 		sampled_tid = context->service_tid;
 		if (sampled_tid) {
-			tid = context->protocols[0].callback(NULL,
+			tid = context->protocols[0].callback(wsi,
 				     LWS_CALLBACK_GET_THREAD_ID, NULL, NULL, 0);
 			if (tid == -1)
 				return -1;
diff --git a/lib/private-libwebsockets.h b/lib/private-libwebsockets.h
index 62a3646d..731deb23 100644
--- a/lib/private-libwebsockets.h
+++ b/lib/private-libwebsockets.h
@@ -502,6 +502,7 @@ struct lws_context {
 	 * for pollfd event change.
 	 */
 	volatile int service_tid;
+	int service_tid_detected;
 #ifndef _WIN32
 	int dummy_pipe_fds[2];
 #endif