diff --git a/libssh/socket.c b/libssh/socket.c
index 9350bcab..b774a984 100644
--- a/libssh/socket.c
+++ b/libssh/socket.c
@@ -54,7 +54,7 @@
 #include "libssh/session.h"
 
 #ifndef _WIN32
-extern const char **environ;
+extern char **environ;
 #endif
 /**
  * @internal