diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 89b4fa815a9b..4b7c9a60a735 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5071,6 +5071,10 @@ static int process_timer_func(struct bpf_verifier_env *env, int regno,
 		verbose(env, "verifier bug. Two map pointers in a timer helper\n");
 		return -EFAULT;
 	}
+	if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
+		verbose(env, "bpf_timer cannot be used for PREEMPT_RT.\n");
+		return -EOPNOTSUPP;
+	}
 	meta->map_uid = reg->map_uid;
 	meta->map_ptr = map;
 	return 0;