diff --git a/src/lib.rs b/src/lib.rs
index 4a8c4b6..60b813d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -167,7 +167,8 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     let max_count = matches.get_one::<u64>("max_count").copied();
     let byte_offset = matches.get_flag("byte_offset");
     let line_number = matches.get_flag("line_number");
-    let line_buffered = matches.get_flag("line_buffered");
+    let stdout_is_terminal = std::io::stdout().is_terminal();
+    let line_buffered = matches.get_flag("line_buffered") || stdout_is_terminal;
     let with_filename = matches.get_flag("with_filename");
     let no_filename = matches.get_flag("no_filename");
     let label = matches
@@ -391,7 +392,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
         ColorMode::Never => false,
         // On Windows, an unset TERM allows color support, matching anstyle-query.
         ColorMode::Auto => {
-            std::io::stdout().is_terminal()
+            stdout_is_terminal
                 && match std::env::var_os("TERM") {
                     Some(term) => term != "dumb",
                     None => cfg!(windows),
diff --git a/src/output.rs b/src/output.rs
index ba1f06a..dc90127 100644
--- a/src/output.rs
+++ b/src/output.rs
@@ -231,7 +231,7 @@ impl<'a> OutputWriter<'a> {
         }
     }
 
-    /// Flush in `--line-buffered` mode.
+    /// Flush for terminal output or explicit `--line-buffered` mode.
     fn maybe_flush(&mut self) -> io::Result<()> {
         if self.config.line_buffered {
             self.out.flush()