diff --git a/meson.build b/meson.build
index 37c14687..ce386a4c 100644
--- a/meson.build
+++ b/meson.build
@@ -46,6 +46,7 @@ have_funcs = [
 	'memfd_create',
 	'mremap',
 	'strndup',
+	'gettid',
 ]
 foreach f: have_funcs
 	config_h.set('HAVE_' + f.underscorify().to_upper(), cc.has_function(f))
diff --git a/src/connection.c b/src/connection.c
index 9c6a6b01..2d1e8d1d 100644
--- a/src/connection.c
+++ b/src/connection.c
@@ -26,6 +26,8 @@
 
 #define _GNU_SOURCE
 
+#include "../config.h"
+
 #include <math.h>
 #include <stdlib.h>
 #include <stdint.h>
@@ -1538,6 +1540,9 @@ wl_closure_print(struct wl_closure *closure, struct wl_object *target,
 		 int send, int discarded, uint32_t (*n_parse)(union wl_argument *arg),
 		 const char *queue_name, int color)
 {
+#if defined(HAVE_GETTID)
+	static int include_tid = -1;
+#endif // defined(HAVE_GETTID)
 	int i;
 	struct argument_details arg;
 	const char *signature = closure->message->signature;
@@ -1558,6 +1563,18 @@ wl_closure_print(struct wl_closure *closure, struct wl_object *target,
 		color ? WL_DEBUG_COLOR_GREEN : "",
 		time / 1000, time % 1000);
 
+#if defined(HAVE_GETTID)
+	if (include_tid < 0) {
+		include_tid = wl_check_env_token(getenv("WAYLAND_DEBUG"), "thread_id");
+	}
+
+	if (include_tid) {
+		fprintf(f, "%sTID#%d ",
+			color ? WL_DEBUG_COLOR_CYAN : "",
+			(int) gettid());
+	}
+#endif
+
 	if (queue_name) {
 		fprintf(f, "%s{%s} ",
 			color ? WL_DEBUG_COLOR_YELLOW : "",