diff --git a/src/uu/du/src/du.rs b/src/uu/du/src/du.rs
index a55156ca3..05167853c 100644
--- a/src/uu/du/src/du.rs
+++ b/src/uu/du/src/du.rs
@@ -269,7 +269,7 @@ fn choose_size(matches: &ArgMatches, stat: &Stat) -> u64 {
     } else if matches.is_present(options::APPARENT_SIZE) || matches.is_present(options::BYTES) {
         stat.size
     } else {
-        // C's stat is such that each block is assume to be 512 bytes
+        // The st_blocks field indicates the number of blocks allocated to the file, 512-byte units.
         // See: http://linux.die.net/man/2/stat
         stat.blocks * 512
     }
diff --git a/tests/by-util/test_du.rs b/tests/by-util/test_du.rs
index 240d929fa..029f5e516 100644
--- a/tests/by-util/test_du.rs
+++ b/tests/by-util/test_du.rs
@@ -490,3 +490,96 @@ fn test_du_threshold() {
         .stdout_does_not_contain("links")
         .stdout_contains("deeper_dir");
 }
+
+#[test]
+fn test_du_apparent_size() {
+    let scene = TestScenario::new(util_name!());
+    let result = scene.ucmd().arg("--apparent-size").succeeds();
+
+    #[cfg(target_os = "linux")]
+    {
+        let result_reference = scene.cmd("du").arg("--apparent-size").run();
+        assert_eq!(result.stdout_str(), result_reference.stdout_str());
+    }
+
+    #[cfg(not(target_os = "linux"))]
+    _du_apparent_size(result.stdout_str());
+}
+
+#[cfg(target_os = "windows")]
+fn _du_apparent_size(s: &str) {
+    assert_eq!(
+        s,
+        "1\t.\\subdir\\deeper\\deeper_dir
+1\t.\\subdir\\deeper
+6\t.\\subdir\\links
+6\t.\\subdir
+6\t.
+"
+    );
+}
+#[cfg(target_vendor = "apple")]
+fn _du_apparent_size(s: &str) {
+    assert_eq!(
+        s,
+        "1\t./subdir/deeper/deeper_dir
+1\t./subdir/deeper
+6\t./subdir/links
+6\t./subdir
+6\t.
+"
+    );
+}
+#[cfg(target_os = "freebsd")]
+fn _du_apparent_size(s: &str) {
+    assert_eq!(
+        s,
+        "1\t./subdir/deeper/deeper_dir
+2\t./subdir/deeper
+6\t./subdir/links
+8\t./subdir
+8\t.
+"
+    );
+}
+#[cfg(all(
+    not(target_vendor = "apple"),
+    not(target_os = "windows"),
+    not(target_os = "freebsd")
+))]
+fn _du_apparent_size(s: &str) {
+    assert_eq!(
+        s,
+        "5\t./subdir/deeper/deeper_dir
+9\t./subdir/deeper
+10\t./subdir/links
+22\t./subdir
+26\t.
+"
+    );
+}
+
+#[test]
+fn test_du_bytes() {
+    let scene = TestScenario::new(util_name!());
+    let result = scene.ucmd().arg("--bytes").succeeds();
+
+    #[cfg(target_os = "linux")]
+    {
+        let result_reference = scene.cmd("du").arg("--bytes").run();
+        assert_eq!(result.stdout_str(), result_reference.stdout_str());
+    }
+
+    #[cfg(target_os = "windows")]
+    result.stdout_contains("5145\t.\\subdir\n");
+    #[cfg(target_vendor = "apple")]
+    result.stdout_contains("5625\t./subdir\n");
+    #[cfg(target_os = "freebsd")]
+    result.stdout_contains("7193\t./subdir\n");
+    #[cfg(all(
+        not(target_vendor = "apple"),
+        not(target_os = "windows"),
+        not(target_os = "freebsd")
+    ))]
+    result.stdout_contains("21529\t./subdir\n");
+}