diff --git a/mapper/src/App.js b/mapper/src/App.js
index 7857ebe..f2f4190 100644
--- a/mapper/src/App.js
+++ b/mapper/src/App.js
@@ -342,7 +342,7 @@ function Menu({duration, setDuration, end, setEnd, slider, setSlider, submenu, s
 			return;
 		}
 
-		const dataToSign = `${shareStart}-${shareEnd}-${apiKey}`;
+		const dataToSign = `owntracks-${shareStart}-${shareEnd}-${apiKey}`;
 		const shareSig = await sha256(dataToSign);
 
 		const params = new URLSearchParams(window.location.search);