diff --git a/docs/system/arm/emulation.rst b/docs/system/arm/emulation.rst
index 965f35d8c9..0acac6347c 100644
--- a/docs/system/arm/emulation.rst
+++ b/docs/system/arm/emulation.rst
@@ -15,6 +15,7 @@ the following architecture extensions:
 - FEAT_DIT (Data Independent Timing instructions)
 - FEAT_DPB (DC CVAP instruction)
 - FEAT_Debugv8p2 (Debug changes for v8.2)
+- FEAT_Debugv8p4 (Debug changes for v8.4)
 - FEAT_DotProd (Advanced SIMD dot product instructions)
 - FEAT_FCMA (Floating-point complex number instructions)
 - FEAT_FHM (Floating-point half-precision multiplication instructions)
diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index 202fd5c46e..88d3cef93e 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -799,7 +799,7 @@ static void aarch64_max_initfn(Object *obj)
     cpu->isar.id_aa64zfr0 = t;
 
     t = cpu->isar.id_aa64dfr0;
-    t = FIELD_DP64(t, ID_AA64DFR0, DEBUGVER, 8);  /* FEAT_Debugv8p2 */
+    t = FIELD_DP64(t, ID_AA64DFR0, DEBUGVER, 9);  /* FEAT_Debugv8p4 */
     t = FIELD_DP64(t, ID_AA64DFR0, PMUVER, 5);    /* FEAT_PMUv3p4 */
     cpu->isar.id_aa64dfr0 = t;
 
diff --git a/target/arm/cpu_tcg.c b/target/arm/cpu_tcg.c
index b6fc3752f2..337598e949 100644
--- a/target/arm/cpu_tcg.c
+++ b/target/arm/cpu_tcg.c
@@ -76,8 +76,8 @@ void aa32_max_features(ARMCPU *cpu)
     cpu->isar.id_pfr2 = t;
 
     t = cpu->isar.id_dfr0;
-    t = FIELD_DP32(t, ID_DFR0, COPDBG, 8);        /* FEAT_Debugv8p2 */
-    t = FIELD_DP32(t, ID_DFR0, COPSDBG, 8);       /* FEAT_Debugv8p2 */
+    t = FIELD_DP32(t, ID_DFR0, COPDBG, 9);        /* FEAT_Debugv8p4 */
+    t = FIELD_DP32(t, ID_DFR0, COPSDBG, 9);       /* FEAT_Debugv8p4 */
     t = FIELD_DP32(t, ID_DFR0, PERFMON, 5);       /* FEAT_PMUv3p4 */
     cpu->isar.id_dfr0 = t;
 }