diff --git a/website/source/docs/runtime/environment.html.md b/website/source/docs/runtime/environment.html.md
index 2305813d7..75a90bbf0 100644
--- a/website/source/docs/runtime/environment.html.md
+++ b/website/source/docs/runtime/environment.html.md
@@ -90,9 +90,9 @@ environment variables.
   </tr>
 </table>
 
-~> Port labels and task names will have any dashes `-` in their names replaced by
-underscores `_` when they're used in environment variable names such as
-`NOMAD_ADDR_<task>_<label>`.
+~> Port labels and task names will have any non-alphanumeric or underscore
+characters in their names replaced by underscores `_` when they're used in
+environment variable names such as `NOMAD_ADDR_<task>_<label>`.
 
 ## Task Identifiers