diff --git a/src/libssh2_priv.h b/src/libssh2_priv.h
index cbf2f53..cb20f5b 100644
--- a/src/libssh2_priv.h
+++ b/src/libssh2_priv.h
@@ -70,6 +70,7 @@
 
 #ifndef WIN32
 #include <sys/socket.h>
+#include <sys/ioctl.h>
 #endif
 
 #ifdef LIBSSH2_LIBGCRYPT