diff --git a/linux-user/main.c b/linux-user/main.c
index d8bb8307efdd081323ee85491d81c561200ca0a9..a0d8ce734b924062ce593ee0f0ce6575bdab66d0 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -548,6 +548,8 @@ static int do_strex(CPUARMState *env)
     case 3:
         segv = get_user_u32(val, addr);
         break;
+    default:
+        abort();
     }
     if (segv) {
         env->cp15.c6_data = addr;