diff --git a/intern/gawain/src/gwn_vertex_array_id.cpp b/intern/gawain/src/gwn_vertex_array_id.cpp
index 5294c6c8e23..d4b89a0f62b 100644
--- a/intern/gawain/src/gwn_vertex_array_id.cpp
+++ b/intern/gawain/src/gwn_vertex_array_id.cpp
@@ -19,6 +19,7 @@
 #include <unordered_set>
 
 #if TRUST_NO_ONE
+#if 0
 extern "C" {
 extern int BLI_thread_is_main(void); // Blender-specific function
 }
@@ -29,6 +30,7 @@ static bool thread_is_main()
 	return BLI_thread_is_main();
 	}
 #endif
+#endif
 
 struct Gwn_Context {
 	GLuint default_vao;