diff --git a/pyod/models/ecod.py b/pyod/models/ecod.py
index ef7d00f0d..c4e01eadf 100644
--- a/pyod/models/ecod.py
+++ b/pyod/models/ecod.py
@@ -138,6 +138,7 @@ def decision_function(self, X):
             The anomaly score of the input samples.
         """
         # use multi-thread execution
+        X = check_array(X)
         if self.n_jobs != 1:
             return self._decision_function_parallel(X)
         if hasattr(self, 'X_train'):
diff --git a/pyod/models/iforest.py b/pyod/models/iforest.py
index f45c69f40..048c4b4c2 100644
--- a/pyod/models/iforest.py
+++ b/pyod/models/iforest.py
@@ -258,7 +258,7 @@ def decision_function(self, X):
         """
         check_is_fitted(self, ['decision_scores_', 'threshold_', 'labels_'])
         # invert outlier scores. Outliers comes with higher outlier scores
-        return invert_order(self.detector_.decision_function(X))
+        return invert_order(self.detector_.decision_function(check_array(X)))
 
     @property
     def estimators_(self):