diff --git a/lib/libc/sparc64/sys/__sparc_utrap_setup.c b/lib/libc/sparc64/sys/__sparc_utrap_setup.c
index 1c8ce3003ac..0f7a22d33f8 100644
--- a/lib/libc/sparc64/sys/__sparc_utrap_setup.c
+++ b/lib/libc/sparc64/sys/__sparc_utrap_setup.c
@@ -48,6 +48,8 @@ static const struct sparc_utrap_install_args uia[] = {
 	sizeof (ua) / sizeof (*ua), ua
 };
 
+void __sparc_utrap_setup(void) __attribute__((constructor));
+
 void
 __sparc_utrap_setup(void)
 {