diff --git a/src/shims/unix/freebsd/foreign_items.rs b/src/shims/unix/freebsd/foreign_items.rs
index 7c843e106e..fe7d4641a9 100644
--- a/src/shims/unix/freebsd/foreign_items.rs
+++ b/src/shims/unix/freebsd/foreign_items.rs
@@ -3,6 +3,7 @@ use rustc_target::spec::abi::Abi;
 
 use crate::*;
 use shims::foreign_items::EmulateForeignItemResult;
+use shims::unix::fs::EvalContextExt as _;
 use shims::unix::thread::EvalContextExt as _;
 
 pub fn is_dyn_sym(_name: &str) -> bool {
@@ -62,6 +63,15 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 this.gen_random(ptr, len)?;
                 this.write_scalar(Scalar::from_target_usize(len, this), dest)?;
             }
+            "ftruncate" => {
+                if this.tcx.sess.target.pointer_width == 32 {
+                    throw_unsup_format!("`ftruncate` is not supported on 32 bits",);
+                }
+                let [fd, length] =
+                    this.check_shim(abi, Abi::C { unwind: false }, link_name, args)?;
+                let result = this.ftruncate64(fd, length)?;
+                this.write_scalar(result, dest)?;
+            }
 
             // errno
             "__error" => {
diff --git a/tests/pass-dep/shims/libc-misc.rs b/tests/pass-dep/shims/libc-misc.rs
index de1acb13cb..e9f9b15795 100644
--- a/tests/pass-dep/shims/libc-misc.rs
+++ b/tests/pass-dep/shims/libc-misc.rs
@@ -238,7 +238,7 @@ fn test_isatty() {
     }
 }
 
-#[cfg(not(target_os = "freebsd"))]
+#[cfg(not(all(target_os = "freebsd", pointer_width = "32")))]
 fn test_posix_mkstemp() {
     use std::ffi::CString;
     use std::ffi::OsStr;
@@ -406,7 +406,7 @@ fn test_reallocarray() {
 fn main() {
     test_posix_gettimeofday();
 
-    #[cfg(not(target_os = "freebsd"))] // FIXME we should support this on FreeBSD as well
+    #[cfg(not(all(target_os = "freebsd", pointer_width = "32")))]
     test_posix_mkstemp();
 
     test_posix_realpath_alloc();