diff --git a/extra/DEVELOPER_DOCS/ExplosionBot.md b/extra/DEVELOPER_DOCS/ExplosionBot.md
index 791b1f229..606fe93a0 100644
--- a/extra/DEVELOPER_DOCS/ExplosionBot.md
+++ b/extra/DEVELOPER_DOCS/ExplosionBot.md
@@ -36,7 +36,7 @@ Some things to note:
   @explosion-bot please test_gpu --run-on spacy-transformers --run-on-branch master --spacy-branch current_pr
   ```
 
-  This will launch the GPU pipeline for the `spacy-transformers` repo on its `master` branch, using the current spaCy PR's branch to build spaCy.
+  This will launch the GPU pipeline for the `spacy-transformers` repo on its `master` branch, using the current spaCy PR's branch to build spaCy. The name of the repository passed to `--run-on` is case-sensitive, e.g: use `spaCy` instead of `spacy`.
 
 - General info about supported commands.