diff --git a/src/rtkcmn.c b/src/rtkcmn.c
index 0eae4ac8196235b1b04faa5c02d48dea3c5ece61..9c1f206f3858c45ef7846b7f92732f7b101745ca 100644
--- a/src/rtkcmn.c
+++ b/src/rtkcmn.c
@@ -127,6 +127,7 @@
 *           2018/10/10 1.44 modify api satexclude()
 *-----------------------------------------------------------------------------*/
 #define _POSIX_C_SOURCE 199506
+#define TRACE
 #include <stdarg.h>
 #include <ctype.h>
 #ifndef WIN32