diff --git a/tile/init.cc b/tile/init.cc
index 2cc3248..8cffe7e 100644
--- a/tile/init.cc
+++ b/tile/init.cc
@@ -139,7 +139,7 @@ void
 Init(int argc, char **argv, std::function<int(int, char **)> cb)
 {
     std::unique_lock<std::mutex> _(init_lock);
-    assert(lib_thread && "ReInitialize!!!");
+    assert(!lib_thread && "ReInitialize!!!");
     const char *my_argv[1] = {"unknown"};
 
     if (!argv) {