diff --git a/gdb/nat/amd64-linux-siginfo.c b/gdb/nat/amd64-linux-siginfo.c
index 99faccabf37..d524cb9f80a 100644
--- a/gdb/nat/amd64-linux-siginfo.c
+++ b/gdb/nat/amd64-linux-siginfo.c
@@ -203,7 +203,7 @@ struct compat_siginfo_t
 };
 
 /* For x32, clock_t in _sigchld is 64bit aligned at 4 bytes.  */
-typedef long __attribute__ ((__aligned__ (4))) compat_x32_clock_t;
+using compat_x32_clock_t [[gnu::aligned (4)]] = long;
 
 struct __attribute__ ((__aligned__ (8))) compat_x32_siginfo_t
 {