diff --git a/src/message_cache.cc b/src/message_cache.cc
index e83bad3..6332925 100644
--- a/src/message_cache.cc
+++ b/src/message_cache.cc
@@ -2,6 +2,7 @@
 // see LICENSE.txt
 
 #include "message_cache.hh"
+#include <pEp/platform.h>
 #include <cassert>
 #include <cstring>
 #include <climits>