diff --git a/proxmox-sys/Cargo.toml b/proxmox-sys/Cargo.toml
index a27bfd8e..175c8910 100644
--- a/proxmox-sys/Cargo.toml
+++ b/proxmox-sys/Cargo.toml
@@ -1,5 +1,6 @@
 [package]
 name = "proxmox-sys"
+# next bump is breaking!
 version = "0.3.2"
 authors = ["Proxmox Support Team <support@proxmox.com>"]
 edition = "2018"
@@ -32,3 +33,6 @@ proxmox-time = { path = "../proxmox-time", version = "1.0.0" }
 default = []
 sortable-macro = ["proxmox-sortable-macro"]
 logrotate = ["zstd"]
+acl = []
+crypt = []
+timer = []
diff --git a/proxmox-sys/src/fs/mod.rs b/proxmox-sys/src/fs/mod.rs
index 4aa06b20..f0bf866d 100644
--- a/proxmox-sys/src/fs/mod.rs
+++ b/proxmox-sys/src/fs/mod.rs
@@ -8,6 +8,7 @@ use nix::sys::stat;
 use nix::unistd::{Gid, Uid};
 use std::os::unix::io::{AsRawFd, RawFd};
 
+#[cfg(feature = "acl")]
 pub mod acl;
 
 mod file;
diff --git a/proxmox-sys/src/lib.rs b/proxmox-sys/src/lib.rs
index 180f2d3c..00dadbd0 100644
--- a/proxmox-sys/src/lib.rs
+++ b/proxmox-sys/src/lib.rs
@@ -1,6 +1,7 @@
 use std::os::unix::ffi::OsStrExt;
 
 pub mod command;
+#[cfg(feature = "crypt")]
 pub mod crypt;
 pub mod email;
 pub mod error;
diff --git a/proxmox-sys/src/linux/mod.rs b/proxmox-sys/src/linux/mod.rs
index fce3b8b4..e1502544 100644
--- a/proxmox-sys/src/linux/mod.rs
+++ b/proxmox-sys/src/linux/mod.rs
@@ -9,6 +9,7 @@ pub mod pid;
 pub mod procfs;
 pub mod pty;
 pub mod socket;
+#[cfg(feature = "timer")]
 pub mod timer;
 pub mod tty;