diff --git a/changedetectionio/__init__.py b/changedetectionio/__init__.py
index 436f41018..08b3b5e49 100644
--- a/changedetectionio/__init__.py
+++ b/changedetectionio/__init__.py
@@ -850,14 +850,14 @@ def changedetection_app(config=None, datastore_o=None):
         # Read as binary and force decode as UTF-8
         # Windows may fail decode in python if we just use 'r' mode (chardet decode exception)
         try:
-            newest_version_file_contents = watch.get_history_snapshot(history[dates[-1]])
+            newest_version_file_contents = watch.get_history_snapshot(dates[-1])
         except Exception as e:
-            newest_version_file_contents = "Unable to read {}.\n".format(history[dates[-1]])
+            newest_version_file_contents = "Unable to read {}.\n".format(dates[-1])
 
         previous_version = request.args.get('previous_version')
-        previous_timestamp = history[dates[-2]]
+        previous_timestamp = dates[-2]
         if previous_version:
-            previous_timestamp= previous_version
+            previous_timestamp = previous_version
 
         try:
             previous_version_file_contents = watch.get_history_snapshot(previous_timestamp)
diff --git a/changedetectionio/model/Watch.py b/changedetectionio/model/Watch.py
index 014e2c220..cf0494da5 100644
--- a/changedetectionio/model/Watch.py
+++ b/changedetectionio/model/Watch.py
@@ -241,6 +241,10 @@ class model(dict):
         bump = self.history
         return self.__newest_history_key
 
+    def get_history_snapshot(self, timestamp):
+        with open(self.history[timestamp], 'r', encoding='utf-8', errors='ignore') as f:
+            return f.read()
+
     # Save some text file to the appropriate path and bump the history
     # result_obj from fetch_site_status.run()
     def save_history_text(self, contents, timestamp, snapshot_id):
@@ -359,9 +363,6 @@ class model(dict):
             return fname
         return False
 
-    def get_history_snapshot(self, timestamp):
-        with open(self.history[timestamp], 'rb', encoding='utf-8', errors='ignore') as f:
-            return f.read()
 
     def pause(self):
         self['paused'] = True