diff --git a/parquet-column/src/main/java/org/apache/parquet/schema/Types.java b/parquet-column/src/main/java/org/apache/parquet/schema/Types.java
index 4e7e8815c2..6d61b508eb 100644
--- a/parquet-column/src/main/java/org/apache/parquet/schema/Types.java
+++ b/parquet-column/src/main/java/org/apache/parquet/schema/Types.java
@@ -59,7 +59,7 @@
  *   // }
  *   Types.requiredGroup()
  *            .required(INT64).named("id")
- *            .required(BINARY).as(UTF8).named("email")
+ *            .optional(BINARY).as(UTF8).named("email")
  *        .named("User")
  * </pre>
  * <p>
@@ -82,7 +82,7 @@
  *   // }
  *   Types.requiredGroup()
  *            .required(INT64).named("id")
- *            .required(BINARY).as(UTF8).named("email")
+ *            .optional(BINARY).as(UTF8).named("email")
  *            .optionalGroup()
  *                .required(BINARY).as(UTF8).named("street")
  *                .required(INT32).named("zipcode")
@@ -161,7 +161,7 @@
  *   // }
  *   Types.buildMessage()
  *            .required(INT64).named("id")
- *            .required(BINARY).as(UTF8).named("email")
+ *            .optional(BINARY).as(UTF8).named("email")
  *            .optionalGroup()
  *                .required(BINARY).as(UTF8).named("street")
  *                .required(INT32).named("zipcode")