diff --git a/pytorch_lightning/root_module/memory.py b/pytorch_lightning/root_module/memory.py
index 4a166d63a5..909f97f119 100644
--- a/pytorch_lightning/root_module/memory.py
+++ b/pytorch_lightning/root_module/memory.py
@@ -33,7 +33,7 @@ class ModelSummary(object):
         mods = list(self.model.modules())
         in_sizes = []
         out_sizes = []
-        input_ = self.example_input_array
+        input_ = self.model.example_input_array
         for i in range(1, len(mods)):
             m = mods[i]
             if type(input_) is list or type(input_) is tuple:
@@ -121,7 +121,7 @@ class ModelSummary(object):
         df['Type'] = self.layer_types
         df['Params'] = self.param_nums
 
-        if self.example_input_array:
+        if self.model.example_input_array:
             df.columns.extend(['In_sizes', 'Out_sizes'])
             df['In_sizes'] = self.in_sizes
             df['Out_sizes'] = self.out_sizes
@@ -134,7 +134,7 @@ class ModelSummary(object):
         self.get_parameter_sizes()
         self.get_parameter_nums()
 
-        if self.example_input_array:
+        if self.model.example_input_array:
             self.get_variable_sizes()
         self.make_summary()