diff --git src/Csocket.cpp src/Csocket.cpp
index eb1066c..eab617a 100644
--- src/Csocket.cpp
+++ src/Csocket.cpp
@@ -47,6 +47,7 @@
 #include <stdio.h>
 #include <openssl/conf.h>
 #include <openssl/engine.h>
+#include <openssl/comp.h>
 #endif /* HAVE_LIBSSL */
 
 #ifdef HAVE_ICU
