diff --git a/ampel-firmware/util.h b/ampel-firmware/util.h
index a64f460c48b9faec111fa72437f568b3c0f9c780..1813292858b6d0e9655f98d8f0497442a6cda082 100644
--- a/ampel-firmware/util.h
+++ b/ampel-firmware/util.h
@@ -38,7 +38,7 @@ class Ampel {
 private:
   static void showFreeSpace();
 public:
-  const char *version = "v0.2.0"; // Update manually after significant changes.
+  const char *version = "v0.2.1-DEV"; // Update manually after significant changes.
   const char *board;
   const char *sensorId;
   uint32_t max_loop_duration;