diff --git a/pyproject.toml b/pyproject.toml
index 86b9e18e1..9b13aec54 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -41,11 +41,13 @@ dynamic = ["version"]
 
 [project.optional-dependencies]
 tqdm = ["tqdm>=4.41.0"]
-zarr = ["zarr>=2.12.0"]
-termset = ["linkml-runtime>=1.5.5",
-           "schemasheets>=0.1.23",
-           "oaklib>=0.5.12",
-           "pyyaml>=6.0.1"]
+zarr = ["zarr>=2.12.0,<3"]
+termset = [
+    "linkml-runtime>=1.5.5",
+    "schemasheets>=0.1.23",
+    "oaklib>=0.5.12",
+    "pyyaml>=6.0.1",
+]
 
 [project.urls]
 "Homepage" = "https://github.com/hdmf-dev/hdmf"