diff --git a/target-microblaze/translate.c b/target-microblaze/translate.c
index 37d250f9f0fbe2b92c52117b0d0a1e238671f9e0..fe53b2e1410b32a3098c67d076f00e287cb35cf1 100644
--- a/target-microblaze/translate.c
+++ b/target-microblaze/translate.c
@@ -1144,6 +1144,12 @@ static void dec_fpu(DisasContext *dc)
 
 static void dec_null(DisasContext *dc)
 {
+    if ((dc->tb_flags & MSR_EE_FLAG)
+          && (dc->env->pvr.regs[2] & PVR2_ILL_OPCODE_EXC_MASK)) {
+        tcg_gen_movi_tl(cpu_SR[SR_ESR], ESR_EC_ILLEGAL_OP);
+        t_gen_raise_exception(dc, EXCP_HW_EXCP);
+        return;
+    }
     qemu_log ("unknown insn pc=%x opc=%x\n", dc->pc, dc->opcode);
     dc->abort_at_next_insn = 1;
 }