diff --git a/libmctp.h b/libmctp.h
index 5c0c9f4..e3a125c 100644
--- a/libmctp.h
+++ b/libmctp.h
@@ -7,6 +7,7 @@
 extern "C" {
 #endif
 
+#include <stdarg.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stddef.h>
@@ -102,6 +103,11 @@
 		void (*free)(void *),
 		void *(realloc)(void *, size_t));
 
+/* environment-specific logging */
+void mctp_set_log_stdio(int level);
+void mctp_set_log_syslog(void);
+void mctp_set_log_custom(void (*fn)(int, const char *, va_list));
+
 
 #ifdef __cplusplus
 }