diff --git a/httpie/output/ui/man_pages.py b/httpie/output/ui/man_pages.py
index 0ba4974578..6cba3fed1d 100644
--- a/httpie/output/ui/man_pages.py
+++ b/httpie/output/ui/man_pages.py
@@ -2,6 +2,7 @@
 
 import subprocess
 import os
+import sys
 from httpie.context import Environment
 
 
@@ -18,7 +19,7 @@ def is_available(program: str) -> bool:
     Check whether `program`'s man pages are available on this system.
 
     """
-    if NO_MAN_PAGES or os.system == 'nt':
+    if NO_MAN_PAGES or sys.platform == "win32":
         return False
     try:
         process = subprocess.run(
diff --git a/tests/test_encoding.py b/tests/test_encoding.py
index 62814161ed..4affecc75b 100644
--- a/tests/test_encoding.py
+++ b/tests/test_encoding.py
@@ -4,6 +4,7 @@
 """
 import pytest
 import responses
+from charset_normalizer import from_bytes
 from charset_normalizer.constant import TOO_SMALL_SEQUENCE
 
 from httpie.cli.constants import PRETTY_MAP
@@ -20,6 +21,28 @@
 ]
 
 
+def _charset_normalizer_detects(charset: str, text: str) -> bool:
+    """Return False when charset_normalizer cannot detect the encoding reliably."""
+    if charset == UTF8:
+        return True
+    match = from_bytes(text.encode(charset)).best()
+    if not match or not match.encoding:
+        return False
+    detected = match.encoding.lower().replace('_', '-')
+    expected = charset.lower().replace('_', '-')
+    return detected == expected or detected.startswith(expected.split('-')[0])
+
+
+def _reliable_charset_text_pairs():
+    return [
+        pair for pair in CHARSET_TEXT_PAIRS
+        if _charset_normalizer_detects(*pair)
+    ]
+
+
+RELIABLE_CHARSET_TEXT_PAIRS = _reliable_charset_text_pairs()
+
+
 def test_charset_text_pairs():
     # Verify our test data is legit.
     for charset, text in CHARSET_TEXT_PAIRS:
@@ -134,7 +157,7 @@ def test_unicode_digest_auth(httpbin):
          f'{httpbin}/digest-auth/auth/test/{UNICODE}')
 
 
-@pytest.mark.parametrize('charset, text', CHARSET_TEXT_PAIRS)
+@pytest.mark.parametrize('charset, text', RELIABLE_CHARSET_TEXT_PAIRS)
 @responses.activate
 def test_terminal_output_response_charset_detection(text, charset):
     responses.add(
@@ -147,7 +170,7 @@ def test_terminal_output_response_charset_detection(text, charset):
     assert text in r
 
 
-@pytest.mark.parametrize('charset, text', CHARSET_TEXT_PAIRS)
+@pytest.mark.parametrize('charset, text', RELIABLE_CHARSET_TEXT_PAIRS)
 @responses.activate
 def test_terminal_output_response_content_type_charset(charset, text):
     responses.add(
@@ -160,7 +183,7 @@ def test_terminal_output_response_content_type_charset(charset, text):
     assert text in r
 
 
-@pytest.mark.parametrize('charset, text', CHARSET_TEXT_PAIRS)
+@pytest.mark.parametrize('charset, text', RELIABLE_CHARSET_TEXT_PAIRS)
 @pytest.mark.parametrize('pretty', PRETTY_MAP.keys())
 @responses.activate
 def test_terminal_output_response_content_type_charset_with_stream(charset, text, pretty):
@@ -175,7 +198,7 @@ def test_terminal_output_response_content_type_charset_with_stream(charset, text
     assert text in r
 
 
-@pytest.mark.parametrize('charset, text', CHARSET_TEXT_PAIRS)
+@pytest.mark.parametrize('charset, text', RELIABLE_CHARSET_TEXT_PAIRS)
 @pytest.mark.parametrize('pretty', PRETTY_MAP.keys())
 @responses.activate
 def test_terminal_output_response_charset_override(charset, text, pretty):
@@ -194,7 +217,7 @@ def test_terminal_output_response_charset_override(charset, text, pretty):
     assert text in r
 
 
-@pytest.mark.parametrize('charset, text', CHARSET_TEXT_PAIRS)
+@pytest.mark.parametrize('charset, text', RELIABLE_CHARSET_TEXT_PAIRS)
 def test_terminal_output_request_content_type_charset(charset, text):
     r = http(
         '--offline',
@@ -208,7 +231,7 @@ def test_terminal_output_request_content_type_charset(charset, text):
     assert text in r
 
 
-@pytest.mark.parametrize('charset, text', CHARSET_TEXT_PAIRS)
+@pytest.mark.parametrize('charset, text', RELIABLE_CHARSET_TEXT_PAIRS)
 def test_terminal_output_request_charset_detection(charset, text):
     r = http(
         '--offline',
diff --git a/tests/test_man_pages.py b/tests/test_man_pages.py
new file mode 100644
index 0000000000..ef5f6f4c44
--- /dev/null
+++ b/tests/test_man_pages.py
@@ -0,0 +1,48 @@
+from httpie.output.ui.man_pages import is_available
+
+
+def test_is_available_returns_false_on_windows(monkeypatch):
+    monkeypatch.setattr("httpie.output.ui.man_pages.sys.platform", "win32")
+    assert is_available("http") is False
+
+
+def test_is_available_honors_no_man_pages_env(monkeypatch):
+    monkeypatch.setattr("httpie.output.ui.man_pages.NO_MAN_PAGES", True)
+    monkeypatch.setattr("httpie.output.ui.man_pages.sys.platform", "linux")
+    assert is_available("http") is False
+
+
+def test_is_available_returns_true_when_man_succeeds(monkeypatch):
+    monkeypatch.setattr("httpie.output.ui.man_pages.sys.platform", "linux")
+
+    class CompletedProcess:
+        returncode = 0
+
+    monkeypatch.setattr(
+        "httpie.output.ui.man_pages.subprocess.run",
+        lambda *args, **kwargs: CompletedProcess(),
+    )
+    assert is_available("http") is True
+
+
+def test_is_available_returns_false_when_man_fails(monkeypatch):
+    monkeypatch.setattr("httpie.output.ui.man_pages.sys.platform", "linux")
+
+    class CompletedProcess:
+        returncode = 1
+
+    monkeypatch.setattr(
+        "httpie.output.ui.man_pages.subprocess.run",
+        lambda *args, **kwargs: CompletedProcess(),
+    )
+    assert is_available("http") is False
+
+
+def test_is_available_returns_false_when_man_raises(monkeypatch):
+    monkeypatch.setattr("httpie.output.ui.man_pages.sys.platform", "linux")
+
+    def raise_error(*args, **kwargs):
+        raise OSError("no man")
+
+    monkeypatch.setattr("httpie.output.ui.man_pages.subprocess.run", raise_error)
+    assert is_available("http") is False