diff --git a/contrib/epee/src/abstract_http_client.cpp b/contrib/epee/src/abstract_http_client.cpp
index 31a98260f..bd9cb0dde 100644
--- a/contrib/epee/src/abstract_http_client.cpp
+++ b/contrib/epee/src/abstract_http_client.cpp
@@ -1,3 +1,4 @@
+#include <math.h>
 #include "net/abstract_http_client.h"
 #include "net/http_base.h"
 #include "net/net_parse_helpers.h"