diff --git a/docs/requirements.txt b/docs/requirements.txt
index ce9a423..1626f39 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -4,6 +4,7 @@ requests
 lxml
 PyYAML
 structlog
+fluent.runtime
 
 sphinx>=3.2
 # <5 has strange bottom margins for p, and no list indicators