diff --git a/CHANGELOG.md b/CHANGELOG.md
index bafa9678f..41542cdef 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,7 +1,7 @@
 # Change log
 
-
 - [#559](https://github.com/mobilityhouse/ocpp/issues/559) Update project dependencies as of 22-12-2023
+- [#421](https://github.com/mobilityhouse/ocpp/issues/421) Type of v16.datatypes.SampledValue.context is incorrect 
 
 ## 0.25.0 (2024-01-08)
 
diff --git a/ocpp/v16/datatypes.py b/ocpp/v16/datatypes.py
index aa652f80d..36c751a7c 100644
--- a/ocpp/v16/datatypes.py
+++ b/ocpp/v16/datatypes.py
@@ -105,7 +105,7 @@ class SampledValue:
     """
 
     value: str
-    context: ReadingContext
+    context: Optional[ReadingContext] = None
     format: Optional[ValueFormat] = None
     measurand: Optional[Measurand] = None
     phase: Optional[Phase] = None