diff --git a/src/uu/cat/src/cat.rs b/src/uu/cat/src/cat.rs
index 67652e4ff..3315c2fe1 100644
--- a/src/uu/cat/src/cat.rs
+++ b/src/uu/cat/src/cat.rs
@@ -462,3 +462,47 @@ fn write_nonprint_to_end<W: Write>(in_buf: &[u8], writer: &mut W, tab: &[u8]) ->
         0
     }
 }
+
+mod tests {
+    use std::io::{BufWriter, stdout};
+
+    #[test]
+    fn test_write_nonprint_to_end_new_line() {
+        let mut writer = BufWriter::with_capacity(1024 * 64, stdout());
+        let in_buf = b"\n";
+        let tab = b"";
+        super::write_nonprint_to_end(in_buf, &mut writer, tab);
+        assert_eq!(writer.buffer().len(), 0);
+    }
+
+    #[test]
+    fn test_write_nonprint_to_end_9() {
+        let mut writer = BufWriter::with_capacity(1024 * 64, stdout());
+        let in_buf = &[9u8];
+        let tab = b"tab";
+        super::write_nonprint_to_end(in_buf, &mut writer, tab);
+        assert_eq!(writer.buffer(), tab);
+    }
+
+    #[test]
+    fn test_write_nonprint_to_end_0_to_8() {
+        for byte in 0u8..=8u8 {
+            let mut writer = BufWriter::with_capacity(1024 * 64, stdout());
+            let in_buf = &[byte];
+            let tab = b"";
+            super::write_nonprint_to_end(in_buf, &mut writer, tab);
+            assert_eq!(writer.buffer(), [b'^', byte + 64]);
+        }
+    }
+
+    #[test]
+    fn test_write_nonprint_to_end_10_to_31() {
+        for byte in 11u8..=31u8 {
+            let mut writer = BufWriter::with_capacity(1024 * 64, stdout());
+            let in_buf = &[byte];
+            let tab = b"";
+            super::write_nonprint_to_end(in_buf, &mut writer, tab);
+            assert_eq!(writer.buffer(), [b'^', byte + 64]);
+        }
+    }
+}