Kafka Streams fails with NPE if record contains null-value in header

[2019-03-14 13:14:49,756] ERROR stream-thread [<mask-app-id>-2-1-1f30b4e6-1204-4aa7-9426-a395ab06ad64-StreamThread-2] Failed to process stream task 9_2 due to the following error: (org.apache.kafka.str
eams.processor.internals.AssignedStreamsTasks)
java.lang.NullPointerException
at org.apache.kafka.streams.processor.internals.ProcessorRecordContext.sizeBytes(ProcessorRecordContext.java:93)
at org.apache.kafka.streams.state.internals.ContextualRecord.sizeBytes(ContextualRecord.java:42)
at org.apache.kafka.streams.state.internals.LRUCacheEntry.<init>(LRUCacheEntry.java:53)
at org.apache.kafka.streams.state.internals.CachingWindowStore.put(CachingWindowStore.java:160)
at org.apache.kafka.streams.state.internals.CachingWindowStore.put(CachingWindowStore.java:36)
at org.apache.kafka.streams.state.internals.MeteredWindowStore.put(MeteredWindowStore.java:114)
at org.apache.kafka.streams.kstream.internals.KStreamWindowAggregate$KStreamWindowAggregateProcessor.process(KStreamWindowAggregate.java:124)
at org.apache.kafka.streams.processor.internals.ProcessorNode.process(ProcessorNode.java:117)
at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.forward(ProcessorContextImpl.java:146)
at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.forward(ProcessorContextImpl.java:129)
at org.apache.kafka.streams.processor.internals.ProcessorContextImpl.forward(ProcessorContextImpl.java:93)
at org.apache.kafka.streams.processor.internals.SourceNode.process(SourceNode.java:84)
at org.apache.kafka.streams.processor.internals.StreamTask.process(StreamTask.java:351)
at org.apache.kafka.streams.processor.internals.AssignedStreamsTasks.process(AssignedStreamsTasks.java:104)
at org.apache.kafka.streams.processor.internals.TaskManager.process(TaskManager.java:413)
at org.apache.kafka.streams.processor.internals.StreamThread.runOnce(StreamThread.java:862)
at org.apache.kafka.streams.processor.internals.StreamThread.runLoop(StreamThread.java:777)
at org.apache.kafka.streams.processor.internals.StreamThread.run(StreamThread.java:747)