diff --git a/qemu/target-arm/translate.c b/qemu/target-arm/translate.c
index eaac67f0..38bda859 100644
--- a/qemu/target-arm/translate.c
+++ b/qemu/target-arm/translate.c
@@ -8239,7 +8239,7 @@ static void disas_arm_insn(DisasContext *s, unsigned int insn)  // qq
             case 4: /* dsb */
             case 5: /* dmb */
                 ARCH(7);
-                /* We don't emulate caches so these are a no-op.  */
+                tcg_gen_mb(tcg_ctx, TCG_MO_ALL | TCG_BAR_SC);
                 return;
             case 6: /* isb */
                 /* We need to break the TB after this insn to execute
@@ -10584,7 +10584,7 @@ static int disas_thumb2_insn(CPUARMState *env, DisasContext *s, uint16_t insn_hw
                             break;
                         case 4: /* dsb */
                         case 5: /* dmb */
-                            /* These execute as NOPs.  */
+                            tcg_gen_mb(tcg_ctx, TCG_MO_ALL | TCG_BAR_SC);
                             break;
                         case 6: /* isb */
                             /* We need to break the TB after this insn