diff --git a/google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1beta2/JsonToProtoMessage.java b/google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1beta2/JsonToProtoMessage.java
index c316df0eef..9c6d831034 100644
--- a/google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1beta2/JsonToProtoMessage.java
+++ b/google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1beta2/JsonToProtoMessage.java
@@ -144,6 +144,26 @@ private static void fillField(
         if (val instanceof ByteString) {
           protoMsg.setField(fieldDescriptor, ((ByteString) val).toByteArray());
           return;
+        } else if (val instanceof JSONArray) {
+          try {
+            byte[] bytes = new byte[((JSONArray) val).length()];
+            for (int j = 0; j < ((JSONArray) val).length(); j++) {
+              bytes[j] = (byte) ((JSONArray) val).getInt(j);
+              if (bytes[j] != ((JSONArray) val).getInt(j)) {
+                throw new IllegalArgumentException(
+                    String.format(
+                        "Error: "
+                            + currentScope
+                            + "["
+                            + j
+                            + "] could not be converted to byte[]."));
+              }
+            }
+            protoMsg.setField(fieldDescriptor, bytes);
+          } catch (JSONException e) {
+            throw new IllegalArgumentException(
+                String.format("Error: " + currentScope + "could not be converted to byte[]."));
+          }
         }
         break;
       case INT64:
@@ -261,6 +281,9 @@ private static void fillRepeatedField(
                           + index
                           + "] could not be converted to byte[]."));
             }
+          } else if (val instanceof ByteString) {
+            protoMsg.addRepeatedField(fieldDescriptor, ((ByteString) val).toByteArray());
+            return;
           } else {
             fail = true;
           }