diff --git a/CMakeLists.txt b/CMakeLists.txt
index ef7506f..5b57637 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,6 +2,7 @@
 
 add_definitions (-DMCTP_LOG_STDERR)
 add_definitions (-DMCTP_HAVE_FILEIO)
+add_definitions (-DMCTP_HAVE_STDIO)
 
 add_library (libmctp STATIC alloc.c core.c log.c libmctp.h serial.c)