diff --git a/_webi/ua-detect.js b/_webi/ua-detect.js
index 27d772a..5455d6c 100644
--- a/_webi/ua-detect.js
+++ b/_webi/ua-detect.js
@@ -10,6 +10,12 @@ function getOs(ua) {
     return 'android';
   } else if (/iOS|iPhone|Macintosh|Darwin|OS\s*X|macOS|mac/i.test(ua)) {
     return 'macos';
+  } else if (/Microsoft\s*Linux/i.test(ua)) {
+    // It's the year of the Linux Desktop!
+    // WSL / WSL2
+    // (checking linux twice because I'm not sure about cygwin / msysgit)
+    // See also http://www.mslinux.org/
+    return 'linux';
   } else if (/^ms$|Microsoft|Windows|win32|win|PowerShell/i.test(ua)) {
     // 'win' must be tested after 'darwin'
     return 'windows';