diff --git a/project.py b/project.py
index 263a549..93b6080 100644
--- a/project.py
+++ b/project.py
@@ -220,7 +220,7 @@ class Project:
         list(self.redactSourcesYield())
 
     def classify(self, sample: Path, tag: str):
-        if tag not in self.tags:
+        if tag != "ignored" and tag not in self.tags:
             raise ValueError(f'Unknown tag "{tag}"')
 
         with self.__sessionmaker() as session: