diff --git a/README.md b/README.md
index a610d50..fc32a78 100644
--- a/README.md
+++ b/README.md
@@ -14,3 +14,6 @@ Send code to Hydra from Neovim
 ```javascript
 solid([1, 0, 0], [0, 1, 0], [0, 0, 1]).out();
 ```
+
+**Note:** If Hydra is not visible (i.e. when you don't have it next to your editor/on
+another screen), the `time` global is only updated roughly once a second.