diff --git a/pyproject.toml b/pyproject.toml
index b43a84b3..26fb6774 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -39,6 +39,7 @@ dependencies = [
     "pandas>=1.0.0",
     "pyphen>=0.11.0,<0.15.0",
     "ftfy>=6.0.3,<6.1.0",
+    "pydantic>=2.0",
 ]
 
 requires-python = ">=3.8"
diff --git a/src/textdescriptives/components/quality_data_classes.py b/src/textdescriptives/components/quality_data_classes.py
index b8251d70..4a5bac79 100644
--- a/src/textdescriptives/components/quality_data_classes.py
+++ b/src/textdescriptives/components/quality_data_classes.py
@@ -2,7 +2,7 @@
 
 from typing import Any, Dict, Optional, Tuple, Union
 
-from pydantic import BaseModel, Extra, Field
+from pydantic import ConfigDict, BaseModel, Field
 
 Interval = Tuple[Optional[float], Optional[float]]
 
@@ -20,9 +20,7 @@ class ThresholdsOutput(BaseModel):
         >>> t_out.passed
         True
     """
-
-    class Config:
-        extra = Extra.forbid
+    model_config = ConfigDict(extra="forbid")
 
     threshold: Union[Interval, bool, None]
     value: Union[float, None]
@@ -60,9 +58,7 @@ def __eq__(self, other: Any) -> bool:
 
 class QualityThresholds(BaseModel):
     """Thresholds for quality metrics."""
-
-    class Config:
-        extra = Extra.forbid
+    model_config = ConfigDict(extra="forbid")
 
     n_stop_words: Interval = Field(
         (2, None),
@@ -163,9 +159,7 @@ class Config:
 
 class QualityOutput(BaseModel):
     """The output of the quality function."""
-
-    class Config:
-        extra = Extra.forbid
+    model_config = ConfigDict(extra="forbid")
 
     n_stop_words: ThresholdsOutput = Field(
         ...,