diff --git a/src/xcb.h b/src/xcb.h
index 148b00c..c17a2ef 100644
--- a/src/xcb.h
+++ b/src/xcb.h
@@ -483,7 +483,7 @@ xcb_connection_t *xcb_connect_to_fd(int fd, xcb_auth_info_t *auth_info);
  * @param c: The connection.
  *
  * Closes the file descriptor and frees all memory associated with the
- * connection @c c.
+ * connection @c c. If @p c is @c NULL, nothing is done.
  */
 void xcb_disconnect(xcb_connection_t *c);
 
diff --git a/src/xcb_conn.c b/src/xcb_conn.c
index ab901a9..fa50985 100644
--- a/src/xcb_conn.c
+++ b/src/xcb_conn.c
@@ -350,7 +350,7 @@ xcb_connection_t *xcb_connect_to_fd(int fd, xcb_auth_info_t *auth_info)
 
 void xcb_disconnect(xcb_connection_t *c)
 {
-    if(is_static_error_conn(c))
+    if(c == NULL || is_static_error_conn(c))
         return;
 
     free(c->setup);