diff --git a/README.md b/README.md
index d552429..aad3c3d 100644
--- a/README.md
+++ b/README.md
@@ -118,10 +118,11 @@ necessary to show a feature.
   call `r.sendError(err, status_code)` when you catch an error and a stack trace
   will be returned to the client / browser.
 - [**HTTPS**](examples/https/https.zig): Shows how easy it is to use facil.io's
-  openssl support. Must be compiled with the environment variable
-  `ZAP_USE_OPENSSL` set to `true` and requires openssl dev dependencies
+  openssl support. Must be compiled with `-Dopenssl=true` or the environment 
+  variable `ZAP_USE_OPENSSL` set to `true` and requires openssl dev dependencies
   (headers, lib) to be installed on the system.
-  - run it like this: `ZAP_USE_OPENSSL=true zig build run-https`
+  - run it like this: `ZAP_USE_OPENSSL=true zig build run-https`  
+    OR like this: `zig build -Dopenssl=true run-https`
   - it will tell you how to generate certificates
 
 I'll continue wrapping more of facil.io's functionality and adding stuff to zap