diff --git a/kats/compat/compat.py b/kats/compat/compat.py
index 818967bc..43abc2b6 100644
--- a/kats/compat/compat.py
+++ b/kats/compat/compat.py
@@ -11,22 +11,34 @@
     # Python < 3.8
     import importlib_metadata as metadata
 
-from typing import Callable, Union
+from typing import Any, Callable, Type, Union
+
+import packaging
 
 from packaging import version as pv
 
+OLD_PACKAGING_VERSION: bool = pv.parse(packaging.__version__) <= pv.parse("21.3")
+
+# type: ignore
+VERSION_TYPE: Type[Any] = (
+    Union[pv.Version, pv.LegacyVersion] if OLD_PACKAGING_VERSION else pv.Version
+)
 
-V = Union[str, "Version", pv.Version, pv.LegacyVersion]
+if OLD_PACKAGING_VERSION:
+    V = Union[str, "Version", pv.Version, pv.LegacyVersion]
+else:
+    V = Union[str, "Version", pv.Version]
 
 
 class Version:
     """Extend packaging Version to allow comparing to version strings.
 
     Wraps instead of extends, because pv.parse can return either a
-    pv.Version or a pv.LegacyVersion.
+    pv.Version or a pv.LegacyVersion for version under 21.3
     """
 
-    version: Union[pv.Version, pv.LegacyVersion]
+    # type: ignore
+    version: VERSION_TYPE
 
     def __init__(self, version: V) -> None:
         """Parse a version.
@@ -36,11 +48,14 @@ def __init__(self, version: V) -> None:
                 version object.
         """
         if isinstance(version, str):
-            self.version = self._parse(version)
+            # type: ignore
+            self.version: VERSION_TYPE = self._parse(version)
         elif isinstance(version, Version):
-            self.version = version.version
+            # type: ignore
+            self.version: VERSION_TYPE = version.version
         else:
-            self.version = version
+            # type: ignore
+            self.version: VERSION_TYPE = version
 
     def _parse(self, version: str) -> Union[pv.Version, pv.LegacyVersion]:
         try:
@@ -73,6 +88,6 @@ def _compare(self, other: V, method: Callable[[V, V], bool]) -> bool:
         elif isinstance(other, str):
             other = self._parse(other)
         try:
-            return method(self.version._key, other._key)
+            return method(self.version._key, other._key)  # type: ignore
         except (AttributeError, TypeError):
             return NotImplemented
diff --git a/requirements.txt b/requirements.txt
index c17e0d00..d65dec6c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,7 @@
 attrs>=21.2.0
 deprecated>=1.2.12
 importlib_metadata; python_version < '3.8'
+holidays<=0.24
 matplotlib>=2.0.0
 numpy>=1.21,<1.22
 pandas>=1.0.4,<=1.3.5