diff --git a/httpie/output/ui/man_pages.py b/httpie/output/ui/man_pages.py
index 0ba4974578..6a83f0d23d 100644
--- a/httpie/output/ui/man_pages.py
+++ b/httpie/output/ui/man_pages.py
@@ -1,6 +1,7 @@
 """Logic for checking and displaying man pages."""
 
 import subprocess
+import sys
 import os
 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_issue_1898_regression.py b/tests/test_issue_1898_regression.py
new file mode 100644
index 0000000000..a97c7fe22c
--- /dev/null
+++ b/tests/test_issue_1898_regression.py
@@ -0,0 +1,6 @@
+
+
+def test_is_available_windows_guard_uses_sys_platform():
+    from httpie.output.ui.man_pages import is_available
+    import sys
+    assert sys.platform != 'win32' or is_available('man') == False