diff --git a/dev-requirements.txt b/dev-requirements.txt
index 0c50f19..9902b41 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -2,3 +2,4 @@ pytest
 pytest-cov
 pytest-mock
 codecov
+chardet==3.0.4
diff --git a/tljh/installer.py b/tljh/installer.py
index cd8da55..f3cc989 100644
--- a/tljh/installer.py
+++ b/tljh/installer.py
@@ -231,6 +231,7 @@ def ensure_jupyterhub_package(prefix):
             "jupyterhub-tmpauthenticator==0.6",
             "oauthenticator==0.10.0",
             "jupyterhub-idle-culler==1.0",
+            "chardet==3.0.4",
         ],
     )
     traefik.ensure_traefik_binary(prefix)