https://bugs.gentoo.org/707452
--- a/sig2str.c
+++ b/sig2str.c
@@ -63,7 +63,7 @@ extern const unsigned int sys_nsigname;	/* also from sys_signame.c */
 #endif
 
 #if !defined(SYS_SIGNAME_DECLARED)
-const char *const sys_signame[];	/* defined in sys_signame.c */
+extern const char *const sys_signame[];	/* defined in sys_signame.c */
 #endif
 
 #if !defined(HAVE_DECL_SIG2STR)
--- a/str2sig.c
+++ b/str2sig.c
@@ -29,7 +29,7 @@ static const char rcsid[] =
 #include "newsyslog.h"		/* generic portability definitions */
 
 #if !defined(SYS_SIGNAME_DECLARED)
-const char *const sys_signame[];		/* defined in signame.c */
+extern const char *const sys_signame[];		/* defined in signame.c */
 #endif
 
 /* NetBSD gained sys_nsig sometime just prior to 1.4 */
@@ -65,7 +65,7 @@ extern const unsigned int sys_nsigname;	/* also from sys_signame.c */
 #endif
 
 #if !defined(SYS_SIGNAME_DECLARED)
-const char *const sys_signame[];	/* defined in sys_signame.c */
+extern const char *const sys_signame[];	/* defined in sys_signame.c */
 #endif
 
 #if !defined(HAVE_DECL_STR2SIG)
--- a/sys_signame.c
+++ b/sys_signame.c
@@ -22,7 +22,7 @@
 #include "config.h"
 #include <sys/types.h>
 
-const char *const sys_signame[] = {
+extern const char *const sys_signame[] = {
 /*  0 */ "Signal 0",	/* Fake value for zero */
 /*  1 */ "HUP",		/* Control TTY hangup */
 /*  2 */ "INT",		/* Control TTY interrupt */