diff --git a/README.md b/README.md
index 071f164..4823b83 100644
--- a/README.md
+++ b/README.md
@@ -28,7 +28,7 @@ NOTE: Can build without unsafe code (the only unsafe code is related to using th
 # Generate sourcemap for the target WASM (replace myproject with your project
 # name).
  cargo wasm2map target/wasm32-unknown-unknown/debug/myproject.wasm \
-    -patch -base-url http://localhost:8080
+    --patch --base-url http://localhost:8080
 
  # Serve the WASM to your browser... (i.e. http://localhost:8080 or wherever
  # your index.html is)