diff --git a/pkgs/by-name/ca/calibre-web/package.nix b/pkgs/by-name/ca/calibre-web/package.nix
index 4f67ba476f80..e857a3ccb0db 100644
--- a/pkgs/by-name/ca/calibre-web/package.nix
+++ b/pkgs/by-name/ca/calibre-web/package.nix
@@ -127,6 +127,8 @@ python3Packages.buildPythonApplication rec {
   pythonRelaxDeps = [
     "apscheduler"
     "bleach"
+    "certifi"
+    "chardet"
     "cryptography"
     "flask"
     "flask-limiter"