diff --git a/core/sip/trans_layer.cpp b/core/sip/trans_layer.cpp
index 26ba19b0..00293d28 100644
--- a/core/sip/trans_layer.cpp
+++ b/core/sip/trans_layer.cpp
@@ -51,6 +51,8 @@
 
 #include <assert.h>
 
+#include <algorithm>
+
 /** 
  * Singleton pointer.
  * @see instance()