diff --git a/src/binary_c_parameters.h b/src/binary_c_parameters.h
index 2c67ee6d95d4343a25aa90a74b47ff204f802ffc..98c98c2880ee6f7a1056150fd9ac041f9a7c1595 100644
--- a/src/binary_c_parameters.h
+++ b/src/binary_c_parameters.h
@@ -1385,7 +1385,7 @@
  * see nucsyn/nucsyn.h for details of parts you can switch on 
  * off.
  ************************************************************/
-#define NUCSYN
+//#define NUCSYN
 
 /************************************************************
  * Stellar colour library