diff --git a/pages/docs/manual/latest/build-configuration.mdx b/pages/docs/manual/latest/build-configuration.mdx
index 99543ffc0..3c548a36a 100644
--- a/pages/docs/manual/latest/build-configuration.mdx
+++ b/pages/docs/manual/latest/build-configuration.mdx
@@ -192,6 +192,8 @@ The warning numbers are shown in the build output when they're triggered. See [W
 
 Extra flags to pass to the compiler. For advanced usages.
 
+- `-open ABC` opens the module `ABC` for each file in the project. `ABC` can either be a dependency, namespaced project or local module of the current project.
+
 ## gentypeconfig
 
 To enable genType, set `"gentypeconfig"` at top level in the project's `rescript.json`.