diff --git a/qemu/target-arm/helper.c b/qemu/target-arm/helper.c
index 74bcbb75..ad63327d 100644
--- a/qemu/target-arm/helper.c
+++ b/qemu/target-arm/helper.c
@@ -4370,7 +4370,7 @@ int bank_number(int mode)
     case ARM_CPU_MODE_MON:
         return 7;
     }
-    //hw_error("bank number requested for bad CPSR mode value 0x%x\n", mode);
+    g_assert_not_reached();
 }
 
 void switch_mode(CPUARMState *env, int mode)