diff --git a/Extensions.md b/Extensions.md
index eb814cd..a3cb8fd 100644
--- a/Extensions.md
+++ b/Extensions.md
@@ -150,7 +150,7 @@ protected void onStartConnection() {
 
 ### Minimalistic interaction; onClick
 
-If the _onClick_ method is overridden by your extension, G-Earth will display a green "Start" button next to your extension and the function will get called on-click. For form extensions, this option is automatically used to open the GUI. For non-gui extensions, this is an additional feature you could use.
+If (and only if) the _onClick_ method is overridden by your extension, G-Earth will display a green "Start" button next to your extension and the function will get called on-click. For form extensions, this option is automatically used to open the GUI. For non-gui extensions, this is an additional feature you could use.
 
 ```java
 @Override