diff --git a/include/cinatra/cinatra.hpp b/include/cinatra/cinatra.hpp
index d83e7baf..2f1b7189 100644
--- a/include/cinatra/cinatra.hpp
+++ b/include/cinatra/cinatra.hpp
@@ -170,7 +170,7 @@ namespace cinatra
 
 	private:
 #ifndef CINATRA_SINGLE_THREAD
-	int num_threads_ = 0;
+	int num_threads_ = 1;
 #else
 	int num_threads_ = std::thread::hardware_concurrency();
 #endif // CINATRA_SINGLE_THREAD