diff --git a/jupyterhub/Dockerfile b/jupyterhub/Dockerfile
index 5bd63c80fb6dbe4c72eacb0f2ee4ceb542c412d2..1e544930388a6907c91e26861b9a34a21d6fd220 100755
--- a/jupyterhub/Dockerfile
+++ b/jupyterhub/Dockerfile
@@ -52,7 +52,7 @@ RUN mkdir -p ~/.venv && \
         JPype1 \
         PySide2 \
         ipykernel \
-        mxnet-cu101>=1.6.0,<1.7.0 \
+        'mxnet-cu101>=1.6.0,<1.7.0' \
         && \
     ipython kernel install --user --name=robofish