diff --git a/pastas/io/base.py b/pastas/io/base.py
index 419ec610..5bd80406 100644
--- a/pastas/io/base.py
+++ b/pastas/io/base.py
@@ -154,6 +154,13 @@ def _load_stressmodel(ts, data):
                         data["parameters"].loc[wnam + "_b", pcol]
                     )
 
+    # Deal with old-style response functions (TODO remove in 1.0)
+    if version.parse(data["file_info"]["pastas_version"]) < version.parse("0.23.0"):
+        if "recharge" in ts.keys():
+            recharge_kwargs = ts.pop("recharge_kwargs", {})
+            recharge_kwargs["class"] = ts["recharge"]
+            ts["recharge"] = recharge_kwargs
+
     # Create and add stress model
     stressmodel = getattr(ps.stressmodels, ts["stressmodel"])
     ts.pop("stressmodel")
@@ -161,8 +168,8 @@ def _load_stressmodel(ts, data):
         rfunc_kwargs = ts.pop("rfunc_kwargs", {})
         ts["rfunc"] = getattr(ps.rfunc, ts["rfunc"])(**rfunc_kwargs)
     if "recharge" in ts.keys():
-        recharge_kwargs = ts.pop("recharge_kwargs", {})
-        ts["recharge"] = getattr(ps.recharge, ts["recharge"])(**recharge_kwargs)
+        recharge_class = ts["recharge"].pop("class")
+        ts["recharge"] = getattr(ps.recharge, recharge_class)(**ts["recharge"])
 
     metadata = []
     settings = []
diff --git a/pastas/recharge.py b/pastas/recharge.py
index ffada375..3a9c90b7 100644
--- a/pastas/recharge.py
+++ b/pastas/recharge.py
@@ -52,10 +52,11 @@
 class RechargeBase:
     """Base class for classes that calculate the recharge."""
 
+    _name = "RechargeBase"
+
     def __init__(self) -> None:
         self.snow = False
         self.nparam = 0
-        self.kwargs = {}
 
     @staticmethod
     def get_init_parameters(name: str = "recharge") -> DataFrame:
@@ -77,6 +78,20 @@ def get_init_parameters(name: str = "recharge") -> DataFrame:
     def simulate(self, prec, evap, p, dt=1.0, return_full=False, **kwargs):
         pass
 
+    def to_dict(self):
+        """Method to export the recharge model object.
+
+        Returns
+        -------
+        data: dict
+            dictionary with all necessary information to reconstruct the StressModel
+            object.
+        """
+        data = {
+            "class": self._name,
+        }
+        return data
+
 
 class Linear(RechargeBase):
     """Linear model for precipitation excess according to
@@ -532,6 +547,23 @@ def check_root_zone_balance(
         error = sr[0] - sr[-1] + (r + ea + q + pe).sum()
         return error
 
+    def to_dict(self):
+        """Method to export the recharge model object.
+
+        Returns
+        -------
+        data: dict
+            dictionary with all necessary information to reconstruct the recharge
+            object.
+        """
+        data = {
+            "class": self._name,
+            "interception": self.interception,
+            "snow": self.snow,
+            "gw_uptake": self.gw_uptake,
+        }
+        return data
+
 
 class Berendrecht(RechargeBase):
     """Recharge to the groundwater calculated according to
diff --git a/pastas/stressmodels.py b/pastas/stressmodels.py
index 5e1072f1..a4fc5dd4 100644
--- a/pastas/stressmodels.py
+++ b/pastas/stressmodels.py
@@ -1351,8 +1351,7 @@ def to_dict(self, series: bool = True) -> dict:
             "rfunc": self.rfunc._name,
             "rfunc_kwargs": self.rfunc.kwargs,
             "name": self.name,
-            "recharge": self.recharge._name,
-            "recharge_kwargs": self.recharge.kwargs,
+            "recharge": self.recharge.to_dict(),
             "cutoff": self.rfunc.cutoff,
             "temp": self.temp.to_dict() if self.temp else None,
         }