diff --git a/Telegram/SourceFiles/boxes/about_box.cpp b/Telegram/SourceFiles/boxes/about_box.cpp
index 3fe076b512..129d59d076 100644
--- a/Telegram/SourceFiles/boxes/about_box.cpp
+++ b/Telegram/SourceFiles/boxes/about_box.cpp
@@ -153,5 +153,8 @@ QString currentVersionText() {
 	} else if (Platform::IsWindowsARM64()) {
 		result += " arm64";
 	}
+#ifdef _DEBUG
+	result += " DEBUG";
+#endif
 	return result;
 }