diff --git a/requirements.txt b/requirements.txt
index fa9e490..2c303b2 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -45,6 +45,7 @@ requests==2.32.3
 requests-html==0.10.0
 retrying==1.3.4
 scipy==1.14.1
+sec-cik-mapper==2.1.0
 setuptools==75.1.0
 sgmllib3k==1.0.0
 six==1.16.0