--- bind-9.16.22.orig/lib/isc/backtrace.c	2021-10-13 12:56:16.000000000 +0200
+++ bind-9.16.22/lib/isc/backtrace.c	2021-10-29 13:57:20.009433814 +0200
@@ -80,10 +80,7 @@ isc_backtrace_gettrace(void **addrs, int
 	return (ISC_R_SUCCESS);
 }
 #elif defined(BACKTRACE_GCC)
-extern int
-_Unwind_Backtrace(void *fn, void *a);
-extern void *
-_Unwind_GetIP(void *ctx);
+#include <unwind.h>
 
 typedef struct {
 	void **result;