diff --git a/utils/generic_utils.py b/utils/generic_utils.py
index 1c7dd5e4..5a811907 100644
--- a/utils/generic_utils.py
+++ b/utils/generic_utils.py
@@ -197,14 +197,19 @@ class KeepAverage():
         self.iters[name] = init_iter
 
     def update_value(self, name, value, weighted_avg=False):
-        if weighted_avg:
-            self.avg_values[name] = 0.99 * self.avg_values[name] + 0.01 * value
-            self.iters[name] += 1
+        if name not in self.avg_values:
+            # add value if not exist before
+            self.add_value(name, init_val=value)
         else:
-            self.avg_values[name] = self.avg_values[name] * \
-                self.iters[name] + value
-            self.iters[name] += 1
-            self.avg_values[name] /= self.iters[name]
+            # else update existing value
+            if weighted_avg:
+                self.avg_values[name] = 0.99 * self.avg_values[name] + 0.01 * value
+                self.iters[name] += 1
+            else:
+                self.avg_values[name] = self.avg_values[name] * \
+                    self.iters[name] + value
+                self.iters[name] += 1
+                self.avg_values[name] /= self.iters[name]
 
     def add_values(self, name_dict):
         for key, value in name_dict.items():