diff --git a/sys/arm64/arm64/gdb_machdep.c b/sys/arm64/arm64/gdb_machdep.c
--- a/sys/arm64/arm64/gdb_machdep.c
+++ b/sys/arm64/arm64/gdb_machdep.c
@@ -55,6 +55,10 @@
 		case GDB_REG_SP:   return (&kdb_frame->tf_sp);
 		case GDB_REG_PC:   return (&kdb_frame->tf_elr);
 		case GDB_REG_CSPR: return (&kdb_frame->tf_spsr);
+		default:
+			if (regnum >= GDB_REG_X0 && regnum <= GDB_REG_X29)
+				return (&kdb_frame->tf_x[regnum - GDB_REG_X0]);
+			break;
 		}
 	}
 	switch (regnum) {