diff --git a/poetry.lock b/poetry.lock
index f259129..d001c6d 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -430,18 +430,19 @@ files = [
 
 [[package]]
 name = "lark"
-version = "0.12.0"
+version = "1.2.2"
 description = "a modern parsing library"
 optional = false
-python-versions = "*"
+python-versions = ">=3.8"
 groups = ["main"]
 files = [
-    {file = "lark-0.12.0-py2.py3-none-any.whl", hash = "sha256:ed1d891cbcf5151ead1c1d14663bf542443e579e63a76ae175b01b899bd854ca"},
-    {file = "lark-0.12.0.tar.gz", hash = "sha256:7da76fcfddadabbbbfd949bbae221efd33938451d90b1fefbbc423c3cccf48ef"},
+    {file = "lark-1.2.2-py3-none-any.whl", hash = "sha256:c2276486b02f0f1b90be155f2c8ba4a8e194d42775786db622faccd652d8e80c"},
+    {file = "lark-1.2.2.tar.gz", hash = "sha256:ca807d0162cd16cef15a8feecb862d7319e7a09bdb13aef927968e45040fed80"},
 ]
 
 [package.extras]
 atomic-cache = ["atomicwrites"]
+interegular = ["interegular (>=0.3.1,<0.4.0)"]
 nearley = ["js2py"]
 regex = ["regex"]
 
@@ -1195,4 +1196,4 @@ type = ["pytest-mypy"]
 [metadata]
 lock-version = "2.1"
 python-versions = "^3.9"
-content-hash = "5c63282e80527865af6025ee3bacf60951fc182b04dffa53dd61a8d23f4fa9bb"
+content-hash = "8987fb22b8e964d6a69c1cad8ed7d6827fcb6dc64eab9f9d1048c9e4aa4fa9d9"
diff --git a/pyproject.toml b/pyproject.toml
index a7355ef..486f0aa 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -22,20 +22,20 @@ readme = "README.rst"
 license = "LICENSE.txt"
 classifiers = [
   "Development Status :: 4 - Beta",
-  "Programming Language :: Python"
+  "Programming Language :: Python",
 ]
-packages = [{ include = "celpy", from = "src"}]
+packages = [{ include = "celpy", from = "src" }]
 
 [tool.poetry.dependencies]
 python = "^3.9"
-lark = "^0.12"
+lark = "^1.1.8"
 python-dateutil = "^2.9.0.post0"
 types-python-dateutil = "^2.9.0.20240316"
 
 # specify as optional for pip install cel-python[c7n] or poetry install -e behavior
 jmespath = { version = "^1.0.1", optional = true }
 pyyaml = { version = "^6.0.1", optional = true }
-types-pyyaml = { version = "^6.0.12.20240311", optional = true}
+types-pyyaml = { version = "^6.0.12.20240311", optional = true }
 
 # specify as a non default group for building automatically in ci without -e
 [tool.poetry.group.c7n.dependencies]
@@ -58,5 +58,5 @@ build-backend = "poetry.core.masonry.api"
 
 [tool.pytest.ini_options]
 markers = [
-    "refactor: tests that need to be refactored to use celfilter_instance"
+  "refactor: tests that need to be refactored to use celfilter_instance",
 ]