diff --git a/src/debug.c b/src/debug.c
index 07624ca..3077e97 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.
@@ -405,9 +410,6 @@
  */
 #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;