diff --git a/src/option.cpp b/src/option.cpp
index 9e01b2106..6e64a6591 100644
--- a/src/option.cpp
+++ b/src/option.cpp
@@ -21,7 +21,7 @@ namespace ncnn {
 Option::Option()
 {
     lightmode = true;
-    num_threads = get_cpu_count();
+    num_threads = get_big_cpu_count();
     blob_allocator = 0;
     workspace_allocator = 0;