diff --git a/.vscode/cspell.dictionaries/workspace.wordlist.txt b/.vscode/cspell.dictionaries/workspace.wordlist.txt
index d4a7b52fb91..e42f24a948d 100644
--- a/.vscode/cspell.dictionaries/workspace.wordlist.txt
+++ b/.vscode/cspell.dictionaries/workspace.wordlist.txt
@@ -154,6 +154,7 @@ IFSOCK
 IRGRP
 IROTH
 IRUSR
+ISDIR
 ISGID
 ISUID
 ISVTX
@@ -205,6 +206,7 @@ setgid
 setgroups
 settime
 setuid
+socketpair
 socktype
 statfs
 statp
diff --git a/Cargo.lock b/Cargo.lock
index d3a59a95d00..99cf61458a0 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1692,6 +1692,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "memoffset"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "488016bfae457b036d996092f6cb448677611ce4449e970ceaf42695203f218a"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "minimal-lexical"
 version = "0.2.1"
@@ -1729,6 +1738,7 @@ dependencies = [
  "cfg-if",
  "cfg_aliases",
  "libc",
+ "memoffset",
 ]
 
 [[package]]
diff --git a/Cargo.toml b/Cargo.toml
index e75f4be5900..d4ae1eb00ef 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -537,7 +537,13 @@ hex-literal = "1.0.0"
 rstest.workspace = true
 
 [target.'cfg(unix)'.dev-dependencies]
-nix = { workspace = true, features = ["process", "signal", "user", "term"] }
+nix = { workspace = true, features = [
+  "process",
+  "signal",
+  "socket",
+  "user",
+  "term",
+] }
 rlimit = "0.10.1"
 xattr.workspace = true
 
diff --git a/src/uucore/src/lib/features/fs.rs b/src/uucore/src/lib/features/fs.rs
index 5c228376d02..b9888654047 100644
--- a/src/uucore/src/lib/features/fs.rs
+++ b/src/uucore/src/lib/features/fs.rs
@@ -720,7 +720,9 @@ pub fn is_stdin_directory(stdin: &Stdin) -> bool {
     {
         use nix::sys::stat::fstat;
         let mode = fstat(stdin.as_fd()).unwrap().st_mode as mode_t;
-        has!(mode, S_IFDIR)
+        // We use the S_IFMT mask ala S_ISDIR() to avoid mistaking
+        // sockets for directories.
+        mode & S_IFMT == S_IFDIR
     }
 
     #[cfg(windows)]
diff --git a/tests/by-util/test_tr.rs b/tests/by-util/test_tr.rs
index 0121f87aa63..491fd64ee02 100644
--- a/tests/by-util/test_tr.rs
+++ b/tests/by-util/test_tr.rs
@@ -1563,3 +1563,24 @@ fn test_broken_pipe_no_error() {
         .run_stdout_starts_with(b"")
         .fails_silently();
 }
+
+#[cfg(not(windows))]
+#[test]
+fn test_stdin_is_socket() {
+    use nix::sys::socket::{AddressFamily, SockFlag, SockType, socketpair};
+    use nix::unistd::write;
+
+    let (fd1, fd2) = socketpair(
+        AddressFamily::Unix,
+        SockType::Stream,
+        None,
+        SockFlag::empty(),
+    )
+    .unwrap();
+    write(fd1, b"::").unwrap();
+    new_ucmd!()
+        .args(&[":", ";"])
+        .set_stdin(fd2)
+        .succeeds()
+        .stdout_is(";;");
+}