diff --git a/requirements.txt b/requirements.txt
index 5e25e9e..f0ed2dd 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -71,7 +71,7 @@ stack-data==0.6.2         # via ipython
 swiglpk==5.0.8            # via cobra, optlang
 sympy==1.11.1             # via optlang
 texttable==1.6.7          # via igraph
-tornado==6.2              # via ipykernel, jupyter-client
+tornado==6.5.7              # via ipykernel, jupyter-client
 tqdm==4.65.0              # via Cobra2D (./setup.cfg)
 traitlets==5.9.0          # via comm, ipykernel, ipython, ipywidgets, jupyter-client, jupyter-core, matplotlib-inline
 typing-extensions==4.5.0  # via Cobra2D (./setup.cfg), pydantic