diff --git a/src/builtins/ulimit.rs b/src/builtins/ulimit.rs
index 2bdde2437..fec376343 100644
--- a/src/builtins/ulimit.rs
+++ b/src/builtins/ulimit.rs
@@ -14,6 +14,7 @@ pub mod limits {
     /// Note these are uints on Linux but ints everywhere else - we use -1 as a sentinel
     /// so cast to int.
     pub mod common {
+        use cfg_if::cfg_if;
         use libc;
         pub const CORE: libc::c_int = libc::RLIMIT_CORE as _;
         pub const DATA: libc::c_int = libc::RLIMIT_DATA as _;
@@ -23,8 +24,15 @@ pub mod common {
         pub const STACK: libc::c_int = libc::RLIMIT_STACK as _;
         pub const CPU: libc::c_int = libc::RLIMIT_CPU as _;
         pub const NPROC: libc::c_int = libc::RLIMIT_NPROC as _;
-        pub const AS: libc::c_int = libc::RLIMIT_AS as _;
+        cfg_if!(
+            if #[cfg(target_os = "openbsd")] {
+                pub const AS: libc::c_int = -1;
+            } else {
+                pub const AS: libc::c_int = libc::RLIMIT_AS as _;
+            }
+        );
     }
+
     pub use self::common::*;
 
     #[cfg(target_os = "linux")]
@@ -68,13 +76,33 @@ pub mod macos {
 
     #[cfg(bsd)]
     pub mod bsd {
+        use cfg_if::cfg_if;
         use libc;
 
-        pub const SBSIZE: libc::c_int = libc::RLIMIT_SBSIZE;
-        pub const RSS: libc::c_int = libc::RLIMIT_RSS;
-        pub const SWAP: libc::c_int = libc::RLIMIT_SWAP;
-        pub const KQUEUES: libc::c_int = libc::RLIMIT_KQUEUES;
-        pub const NPTS: libc::c_int = libc::RLIMIT_NPTS;
+        cfg_if!(
+            if #[cfg(any(target_os = "netbsd", target_os = "openbsd"))] {
+                #[cfg(target_os = "netbsd")]
+                pub const SBSIZE: libc::c_int = libc::RLIMIT_SBSIZE;
+                #[cfg(target_os = "openbsd")]
+                pub const SBSIZE: libc::c_int = -1;
+                pub const RSS: libc::c_int = libc::RLIMIT_RSS;
+                pub const SWAP: libc::c_int = -1;
+                pub const KQUEUES: libc::c_int = -1;
+            } else {
+                pub const SBSIZE: libc::c_int = libc::RLIMIT_SBSIZE;
+                pub const RSS: libc::c_int = libc::RLIMIT_RSS;
+                pub const SWAP: libc::c_int = libc::RLIMIT_SWAP;
+                pub const KQUEUES: libc::c_int = libc::RLIMIT_KQUEUES;
+            }
+        );
+
+        cfg_if!(
+            if #[cfg(target_os = "freebsd")] {
+                pub const NPTS: libc::c_int = libc::RLIMIT_NPTS;
+            } else {
+                pub const NPTS: libc::c_int = -1;
+            }
+        );
 
         pub const NICE: libc::c_int = -1;
         pub const NTHR: libc::c_int = -1;
diff --git a/src/env/environment.rs b/src/env/environment.rs
index 16f749c7a..5237b6bcf 100644
--- a/src/env/environment.rs
+++ b/src/env/environment.rs
@@ -26,6 +26,7 @@
 use crate::wcstringutil::join_strings;
 use crate::wutil::{fish_wcstol, wgetcwd, wgettext};
 
+use cfg_if::cfg_if;
 use libc::{c_int, uid_t};
 use once_cell::sync::{Lazy, OnceCell};
 use std::collections::HashMap;
@@ -567,11 +568,16 @@ fn setup_user(vars: &EnvStack) {
 
 pub(crate) static FALLBACK_PATH: Lazy<&[WString]> = Lazy::new(|| {
     // _CS_PATH: colon-separated paths to find POSIX utilities. Same as USER_CS_PATH.
-    // BSDs only have the "USER_" form, while Linux only has the "CS_" form.
-    #[cfg(any(apple, bsd))]
-    let cs_path = libc::USER_CS_PATH;
-    #[cfg(not(any(apple, bsd)))]
-    let cs_path = libc::_CS_PATH;
+    cfg_if!(
+        // TODO use _CS_PATH (https://github.com/rust-lang/libc/pull/4738)
+        if #[cfg(any(target_os = "netbsd", target_os = "openbsd"))] {
+           let  cs_path = 1;
+        } else if #[cfg(bsd)] {
+           let  cs_path = libc::USER_CS_PATH;
+        } else {
+           let  cs_path = libc::_CS_PATH;
+        }
+    );
 
     let buf_size = unsafe { libc::confstr(cs_path, std::ptr::null_mut(), 0) };
     let paths: Vec<WString> = if buf_size > 0 {