diff --git a/hw/core/machine.c b/hw/core/machine.c
index d970f753e3702..de1547994c4d7 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -36,7 +36,9 @@
 #include "hw/virtio/virtio-iommu.h"
 #include "audio/audio.h"
 
-GlobalProperty hw_compat_9_2[] = {};
+GlobalProperty hw_compat_9_2[] = {
+    {"arm-cpu", "backcompat-pauth-default-use-qarma5", "true"},
+};
 const size_t hw_compat_9_2_len = G_N_ELEMENTS(hw_compat_9_2);
 
 GlobalProperty hw_compat_9_1[] = {
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 1afa07511e38e..68f1ab639b88d 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -2652,6 +2652,8 @@ static const Property arm_cpu_properties[] = {
     DEFINE_PROP_INT32("core-count", ARMCPU, core_count, -1),
     /* True to default to the backward-compat old CNTFRQ rather than 1Ghz */
     DEFINE_PROP_BOOL("backcompat-cntfrq", ARMCPU, backcompat_cntfrq, false),
+    DEFINE_PROP_BOOL("backcompat-pauth-default-use-qarma5", ARMCPU,
+                      backcompat_pauth_default_use_qarma5, false),
     DEFINE_PROP_END_OF_LIST()
 };
 
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index b7500bebd7f11..276a7a557bace 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -972,6 +972,9 @@ struct ArchCPU {
     /* QOM property to indicate we should use the back-compat CNTFRQ default */
     bool backcompat_cntfrq;
 
+    /* QOM property to indicate we should use the back-compat QARMA5 default */
+    bool backcompat_pauth_default_use_qarma5;
+
     /* Specify the number of cores in this CPU cluster. Used for the L2CTLR
      * register.
      */
diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index 4eff05a622eef..045b94fcb4d73 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -529,15 +529,25 @@ void arm_cpu_pauth_finalize(ARMCPU *cpu, Error **errp)
                 return;
             }
 
-            if (cpu->prop_pauth_qarma5) {
+            bool use_default = !cpu->prop_pauth_qarma5 &&
+                               !cpu->prop_pauth_qarma3 &&
+                               !cpu->prop_pauth_impdef;
+
+            if (cpu->prop_pauth_qarma5 ||
+                (use_default &&
+                 cpu->backcompat_pauth_default_use_qarma5)) {
                 isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, APA, features);
                 isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, GPA, 1);
             } else if (cpu->prop_pauth_qarma3) {
                 isar2 = FIELD_DP64(isar2, ID_AA64ISAR2, APA3, features);
                 isar2 = FIELD_DP64(isar2, ID_AA64ISAR2, GPA3, 1);
-            } else { /* default is pauth-impdef */
+            } else if (cpu->prop_pauth_impdef ||
+                       (use_default &&
+                        !cpu->backcompat_pauth_default_use_qarma5)) {
                 isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, API, features);
                 isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, GPI, 1);
+            } else {
+                g_assert_not_reached();
             }
         } else if (cpu->prop_pauth_impdef ||
                    cpu->prop_pauth_qarma3 ||