diff --git a/chromaterm/__main__.py b/chromaterm/__main__.py
index bf3b0fd..ed0f40c 100644
--- a/chromaterm/__main__.py
+++ b/chromaterm/__main__.py
@@ -345,7 +345,7 @@ def process_input(config, data_fd, forward_fd=None, max_wait=None):
                 buffer = data + separator
             # A single character indicates keyboard typing; don't highlight
             # Account for backspaces added by some shells, like zsh
-            elif 0 < len(data_read) < 2 + data_read.count(b'\b') * 2:
+            elif 0 < len(buffer) < 2 + data_read.count(b'\b') * 2:
                 sys.stdout.buffer.write(data + separator)
                 buffer = b''
             # There's more data; fetch it before highlighting, if buffer isn't full
diff --git a/tests/test__main__.py b/tests/test__main__.py
index 7c63206..0ef6942 100644
--- a/tests/test__main__.py
+++ b/tests/test__main__.py
@@ -586,12 +586,13 @@ def test_process_input_read_size(capsys, pcre):
     assert capsys.readouterr().out == '\x1b[1m' + 'x' * write_size + '\x1b[22m'
 
 
-def test_process_input_single_character(capsys, pcre):
+def test_process_input_single_character(capsys, monkeypatch, pcre):
     '''Input processing for a single character. Even with a rule that matches
     single character, the output should not be highlighted as it is typically
     just keyboard input.'''
     pipe_r, pipe_w = os.pipe()
     config = chromaterm.__main__.Config()
+    run_once = threading.Event()
 
     rule = chromaterm.Rule('x', chromaterm.Color('bold'), pcre=pcre)
     config.rules.append(rule)
@@ -601,11 +602,22 @@ def test_process_input_single_character(capsys, pcre):
 
     assert capsys.readouterr().out == 'x'
 
-    # A single character after a separator is not keyboard input
-    os.write(pipe_w, b'hi\nx')
+    # A single character in a trailing chunk is not considered keyboard input
+    def patched_read_ready(*_, timeout=None):
+        # If timeout is used, then it's the call to check for more data
+        if timeout and not run_once.is_set():
+            # Write a single character to attempt to trick it into thinking it's keyboard input
+            os.write(pipe_w, b'x')
+            os.close(pipe_w)
+            run_once.set()
+
+        return [pipe_r]
+
+    monkeypatch.setattr(chromaterm.__main__, 'read_ready', patched_read_ready)
+    os.write(pipe_w, b'hi')
     chromaterm.__main__.process_input(config, pipe_r, max_wait=0)
 
-    assert capsys.readouterr().out == 'hi\n\x1b[1mx\x1b[22m'
+    assert capsys.readouterr().out == 'hi\x1b[1mx\x1b[22m'
 
 
 def test_process_input_socket(capsys):