diff --git a/pypesto/sample/pymc.py b/pypesto/sample/pymc.py
index c6b37e3fa..fc0d08d84 100644
--- a/pypesto/sample/pymc.py
+++ b/pypesto/sample/pymc.py
@@ -3,9 +3,8 @@
 from __future__ import annotations
 
 import logging
-from typing import Union
+from typing import TYPE_CHECKING, Union
 
-import arviz as az
 import numpy as np
 import pymc
 import pytensor.tensor as pt
@@ -16,6 +15,9 @@
 from ..result import McmcPtResult
 from .sampler import Sampler, SamplerImportError
 
+if TYPE_CHECKING:
+    import arviz as az
+
 logger = logging.getLogger(__name__)
 
 # implementation based on: