diff --git a/wpilibc/src/main/native/include/frc/I2C.h b/wpilibc/src/main/native/include/frc/I2C.h
index 4623c44be3..a0860e0552 100644
--- a/wpilibc/src/main/native/include/frc/I2C.h
+++ b/wpilibc/src/main/native/include/frc/I2C.h
@@ -1,5 +1,5 @@
 /*----------------------------------------------------------------------------*/
-/* Copyright (c) 2008-2018 FIRST. All Rights Reserved.                        */
+/* Copyright (c) 2008-2019 FIRST. All Rights Reserved.                        */
 /* Open Source Software - may be modified and shared by FRC teams. The code   */
 /* must be accompanied by the FIRST BSD license file in the root directory of */
 /* the project.                                                               */
@@ -42,7 +42,9 @@ class I2C : public ErrorBase {
    * Generic transaction.
    *
    * This is a lower-level interface to the I2C hardware giving you more control
-   * over each transaction.
+   * over each transaction. If you intend to write multiple bytes in the same
+   * transaction and do not plan to receive anything back, use writeBulk()
+   * instead. Calling this with a receiveSize of 0 will result in an error.
    *
    * @param dataToSend   Buffer of data to send as part of the transaction.
    * @param sendSize     Number of bytes to send as part of the transaction.
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/I2C.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/I2C.java
index a408e47396..1be539097c 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/I2C.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/I2C.java
@@ -67,7 +67,9 @@ public class I2C implements AutoCloseable {
    * Generic transaction.
    *
    * <p>This is a lower-level interface to the I2C hardware giving you more control over each
-   * transaction.
+   * transaction. If you intend to write multiple bytes in the same transaction and do not
+   * plan to receive anything back, use writeBulk() instead. Calling this with a receiveSize
+   * of 0 will result in an error.
    *
    * @param dataToSend   Buffer of data to send as part of the transaction.
    * @param sendSize     Number of bytes to send as part of the transaction.