diff --git a/data/ecosystems/e/ethereum-classic.toml b/data/ecosystems/e/ethereum-classic.toml
index f5c57275..807bf9c5 100644
--- a/data/ecosystems/e/ethereum-classic.toml
+++ b/data/ecosystems/e/ethereum-classic.toml
@@ -179,3 +179,4 @@ url = "https://github.com/ethereumproject/wiki"
 
 [[repo]]
 url = "https://github.com/input-output-hk/mantis"
+tags = ["Protocol"]