diff --git a/include/common/debug.h b/include/common/debug.h
index 333203dd2..f43258e92 100644
--- a/include/common/debug.h
+++ b/include/common/debug.h
@@ -70,6 +70,7 @@
 
 struct task;
 struct buffer;
+extern volatile unsigned long threads_to_dump;
 void ha_task_dump(struct buffer *buf, const struct task *task, const char *pfx);
 void ha_thread_dump(struct buffer *buf, int thr, int calling_tid);
 void ha_thread_dump_all_to_trash();
diff --git a/src/debug.c b/src/debug.c
index 9f538b660..0522f88bf 100644
--- a/src/debug.c
+++ b/src/debug.c
@@ -29,6 +29,11 @@
 #include <proto/stream_interface.h>
 #include <proto/task.h>
 
+/* mask of threads still having to dump, used to respect ordering. Only used
+ * when USE_THREAD_DUMP is set.
+ */
+volatile unsigned long threads_to_dump = 0;
+
 /* Dumps to the buffer some known information for the desired thread, and
  * optionally extra info for the current thread. The dump will be appended to
  * the buffer, so the caller is responsible for preliminary initializing it.
@@ -404,9 +409,6 @@ void ha_thread_dump_all_to_trash()
  */
 #define DEBUGSIG SIGURG
 
-/* mask of threads still having to dump, used to respect ordering */
-static volatile unsigned long threads_to_dump;
-
 /* ID of the thread requesting the dump */
 static unsigned int thread_dump_tid;
 
diff --git a/src/wdt.c b/src/wdt.c
index 19d36c34d..aa89fd443 100644
--- a/src/wdt.c
+++ b/src/wdt.c
@@ -75,7 +75,7 @@ void wdt_handler(int sig, siginfo_t *si, void *arg)
 		if (n - p < 1000000000UL)
 			goto update_and_leave;
 
-		if ((threads_harmless_mask|sleeping_thread_mask) & (1UL << thr)) {
+		if ((threads_harmless_mask|sleeping_thread_mask|threads_to_dump) & (1UL << thr)) {
 			/* This thread is currently doing exactly nothing
 			 * waiting in the poll loop (unlikely but possible),
 			 * waiting for all other threads to join the rendez-vous