diff --git a/python/fbprophet/models.py b/python/fbprophet/models.py
index c75bc93..59a741a 100644
--- a/python/fbprophet/models.py
+++ b/python/fbprophet/models.py
@@ -87,20 +87,18 @@ class CmdStanPyBackend(IStanBackend):
 
     def fit(self, stan_init, stan_data, **kwargs):
         (stan_init, stan_data) = self.prepare_data(stan_init, stan_data)
-        if 'init' in kwargs:
-            kwargs['init'] = self.prepare_data(kwargs['init'], stan_data)[0]
+        
+        if 'inits' not in kwargs and 'init' in kwargs:
+            kwargs['inits'] = self.prepare_data(kwargs['init'], stan_data)[0]
 
         args = dict(
             data=stan_data,
-            init=stan_init,
+            inits=stan_init,
             algorithm='Newton' if stan_data['T'] < 100 else 'LBFGS',
             iter=int(1e4),
         )
         args.update(kwargs)
 
-        args['inits'] = args['init']
-        del args['init']
-
         try:
             self.stan_fit = self.model.optimize(**args)
         except RuntimeError as e:
@@ -122,12 +120,13 @@ class CmdStanPyBackend(IStanBackend):
 
     def sampling(self, stan_init, stan_data, samples, **kwargs) -> dict:
         (stan_init, stan_data) = self.prepare_data(stan_init, stan_data)
-        if 'init' in kwargs:
-            kwargs['init'] = self.prepare_data(kwargs['init'], stan_data)[0]
+        
+        if 'inits' not in kwargs and 'init' in kwargs:
+            kwargs['inits'] = self.prepare_data(kwargs['init'], stan_data)[0]
 
         args = dict(
             data=stan_data,
-            init=stan_init,
+            inits=stan_init,
             algorithm='Newton' if stan_data['T'] < 100 else 'LBFGS',
         )
 
@@ -140,9 +139,6 @@ class CmdStanPyBackend(IStanBackend):
         
         args.update(kwargs)
 
-        args['inits'] = args['init']
-        del args['init']
-
         self.stan_fit = self.model.sample(**args)
         res = self.stan_fit.sample
         (samples, c, columns) = res.shape