diff --git a/pyproject.toml b/pyproject.toml
index a5c59abc..559f3b38 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -58,7 +58,7 @@ lnt = "lnt.lnttool:main"
 
 [project.optional-dependencies]
 server = [
-    "gunicorn>=19.9.0",
+    "gunicorn",
     "psycopg2>=2.9.0",
 ]
 dev = [
@@ -66,7 +66,7 @@ dev = [
     "filecheck",
     "Flake8-pyproject",
     "flake8",
-    "gunicorn>=19.9.0",
+    "gunicorn",
     "lit",
     "psycopg2>=2.9.0",
     "tox",
diff --git a/requirements.server.txt b/requirements.server.txt
index b5c42a43..bcd14ee9 100644
--- a/requirements.server.txt
+++ b/requirements.server.txt
@@ -2,5 +2,5 @@
 # The server has more requirements than the client.
 .
 -r requirements.client.txt
-gunicorn==19.9.0
+gunicorn==23.0.0
 psycopg2==2.9.10