diff --git a/README.md b/README.md
index 254a635..a6fd140 100644
--- a/README.md
+++ b/README.md
@@ -52,7 +52,7 @@
     SECRET_KEY_BASE=As0fZsJlUpuFYSthRjT5Yflg/NlxkFKPRro72xMLXF8yInZ60s6xGGXYVqml+XN1
     ```
 
-    Make sure `$BASE_URL` is set to the actual domain where you plan to host the service. The domain must have a DNS entry pointing to your server for proper resolution and automatic Let's Encrypt TLS certificate issuance. More on that in the next step.
+    Make sure `$BASE_URL` is set to the actual domain where you plan to host the service. The domain must have a DNS entry pointing to your server for proper resolution and automatic Let's Encrypt TLS certificate issuance. More on that in the next step. Also ensure `$SECRET_KEY_BASE` is set to a secure 64-byte string.
 
 1. Expose Plausible server to the web with a [compose override file:](https://github.com/plausible/community-edition/wiki/compose-override)