diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index c98dfb17a8..534c3ff5f3 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -3429,9 +3429,11 @@ static void disas_ldst_pac(DisasContext *s, uint32_t insn,
 
     if (s->pauth_active) {
         if (use_key_a) {
-            gen_helper_autda(dirty_addr, cpu_env, dirty_addr, cpu_X[31]);
+            gen_helper_autda(dirty_addr, cpu_env, dirty_addr,
+                             new_tmp_a64_zero(s));
         } else {
-            gen_helper_autdb(dirty_addr, cpu_env, dirty_addr, cpu_X[31]);
+            gen_helper_autdb(dirty_addr, cpu_env, dirty_addr,
+                             new_tmp_a64_zero(s));
         }
     }