diff --git a/file.go b/file.go
index ac3ac30fc..426c1f75a 100644
--- a/file.go
+++ b/file.go
@@ -361,9 +361,10 @@ func (f *File) setBatchesFromJSON(bs []byte) error {
 	}
 	// Add new batches to file
 	for i := range batches.Batches {
-		if batches.Batches[i] == nil {
+		if batches.Batches[i] == nil || batches.Batches[i].Header == nil {
 			continue
 		}
+
 		batch := *batches.Batches[i]
 		batch.SetID(batch.Header.ID)
 		batch.SetValidation(f.validateOpts)
@@ -390,11 +391,12 @@ func (f *File) setBatchesFromJSON(bs []byte) error {
 
 	// Add new iatBatches to file
 	for i := range iatBatches.IATBatches {
-		if len(iatBatches.IATBatches) == 0 {
+		iatBatch := iatBatches.IATBatches[i]
+
+		if iatBatch.Header == nil {
 			continue
 		}
 
-		iatBatch := iatBatches.IATBatches[i]
 		iatBatch.ID = iatBatch.Header.ID
 		iatBatch.SetValidation(f.validateOpts)
 
diff --git a/server/test/unordered_batches/unordered_batch_test.go b/server/test/unordered_batches/unordered_batch_test.go
index 110c463b3..b2dc961ef 100644
--- a/server/test/unordered_batches/unordered_batch_test.go
+++ b/server/test/unordered_batches/unordered_batch_test.go
@@ -52,7 +52,5 @@ func TestUnorderedBatches(t *testing.T) {
 	server.Handler.ServeHTTP(w, req)
 	w.Flush()
 
-	fmt.Printf("\n%s\n", w.Body.String())
-
 	require.Equal(t, http.StatusOK, w.Code)
 }
diff --git a/test/fuzz/testdata/fuzz/FuzzReaderWriterJSON/e499142d79b69666 b/test/fuzz/testdata/fuzz/FuzzReaderWriterJSON/e499142d79b69666
new file mode 100644
index 000000000..fe560eea4
--- /dev/null
+++ b/test/fuzz/testdata/fuzz/FuzzReaderWriterJSON/e499142d79b69666
@@ -0,0 +1,2 @@
+go test fuzz v1
+string("{\"BAtChes\":[{\"BAtChHeAder\":null}]}")
\ No newline at end of file
diff --git a/test/fuzz/testdata/fuzz/FuzzReaderWriterJSON/iat-nil-header.txt b/test/fuzz/testdata/fuzz/FuzzReaderWriterJSON/iat-nil-header.txt
new file mode 100644
index 000000000..00c7f2427
--- /dev/null
+++ b/test/fuzz/testdata/fuzz/FuzzReaderWriterJSON/iat-nil-header.txt
@@ -0,0 +1,2 @@
+go test fuzz v1
+string("{\"iatBatches\":[{\"IATBatchHeader\":null}]}")