diff --git a/include/libsys/fmt.h b/include/libsys/fmt.h
index d40c44754..94430035c 100644
--- a/include/libsys/fmt.h
+++ b/include/libsys/fmt.h
@@ -9,7 +9,7 @@
 #include <errno.h>
 
 #define INCLUDE_FLOATS
-#undef _SIMPLE_IO
+//#undef _SIMPLE_IO
 
 #ifdef __FLEXC__