diff --git a/base/sysinfo.jl b/base/sysinfo.jl
index 05cf4f2d77a43..0d36e24af963a 100644
--- a/base/sysinfo.jl
+++ b/base/sysinfo.jl
@@ -534,7 +534,7 @@ including e.g. a WebAssembly JavaScript embedding in a web browser.
 isjsvm(os::Symbol) = (os === :Emscripten)
 
 """
-    Sys.detectwsl([os])
+    Sys.detectwsl()
 
 Runtime predicate for testing if Julia is running inside
 Windows Subsystem for Linux (WSL).