diff --git a/wpimath/src/main/java/edu/wpi/first/math/kinematics/DifferentialDriveKinematics.java b/wpimath/src/main/java/edu/wpi/first/math/kinematics/DifferentialDriveKinematics.java
index c11553f2474..d67a7816475 100644
--- a/wpimath/src/main/java/edu/wpi/first/math/kinematics/DifferentialDriveKinematics.java
+++ b/wpimath/src/main/java/edu/wpi/first/math/kinematics/DifferentialDriveKinematics.java
@@ -121,11 +121,10 @@ public DifferentialDriveWheelPositions copy(DifferentialDriveWheelPositions posi
   }
 
   @Override
-  public DifferentialDriveWheelPositions copyInto(
-      DifferentialDriveWheelPositions positions, DifferentialDriveWheelPositions buffer) {
-    buffer.leftMeters = positions.leftMeters;
-    buffer.rightMeters = positions.rightMeters;
-    return buffer;
+  public void copyInto(
+      DifferentialDriveWheelPositions positions, DifferentialDriveWheelPositions output) {
+    output.leftMeters = positions.leftMeters;
+    output.rightMeters = positions.rightMeters;
   }
 
   @Override
diff --git a/wpimath/src/main/java/edu/wpi/first/math/kinematics/Kinematics.java b/wpimath/src/main/java/edu/wpi/first/math/kinematics/Kinematics.java
index 90fc08cf79d..307999d6552 100644
--- a/wpimath/src/main/java/edu/wpi/first/math/kinematics/Kinematics.java
+++ b/wpimath/src/main/java/edu/wpi/first/math/kinematics/Kinematics.java
@@ -49,43 +49,17 @@ public interface Kinematics<S, P> extends Interpolator<P> {
   /**
    * Returns a copy of the wheel positions object.
    *
-   * <p>Implementation note:
-   *
-   * <ul>
-   *   <li>If {@code P} is (deeply) immutable, this should return {@code positions}.
-   *   <li>Otherwise, a new copy should be created and returned.
-   * </ul>
-   *
    * @param positions The wheel positions object to copy.
    * @return A copy.
    */
   P copy(P positions);
 
   /**
-   * Returns a copy of the wheel positions object, possibly reusing storage in the buffer.
-   *
-   * <p>This is meant to be used like this:
-   *
-   * <pre>
-   * m_buffer = m_kinematics.copyInto(positions, m_buffer);
-   * </pre>
-   *
-   * <p>Implementation note:
-   *
-   * <ul>
-   *   <li>If {@code P} is (deeply) immutable, then like {@link #copy}, this should return {@code
-   *       positions}.
-   *   <li>If {@code P} is completely mutable, then this should copy into {@code buffer} and return
-   *       it.
-   *   <li>Otherwise (some members are immutable and some are mutable), a new copy should be created
-   *       and returned.
-   * </ul>
+   * Copies the value of the wheel positions object into the output.
    *
-   * @param positions The wheel positions object to copy. Must not be modified.
-   * @param buffer A buffer available for overwriting. The state after the call is undefined.
-   * @return The copy. Identity is undefined.
+   * @param positions The wheel positions object to copy. Will not be modified.
+   * @param output The output variable of the copy operation. Will have the same value as the
+   *     positions object after the call.
    */
-  default P copyInto(P positions, P buffer) {
-    return copy(positions);
-  }
+  void copyInto(P positions, P output);
 }
diff --git a/wpimath/src/main/java/edu/wpi/first/math/kinematics/MecanumDriveKinematics.java b/wpimath/src/main/java/edu/wpi/first/math/kinematics/MecanumDriveKinematics.java
index 522cdcccfa9..26108088c63 100644
--- a/wpimath/src/main/java/edu/wpi/first/math/kinematics/MecanumDriveKinematics.java
+++ b/wpimath/src/main/java/edu/wpi/first/math/kinematics/MecanumDriveKinematics.java
@@ -267,13 +267,11 @@ public MecanumDriveWheelPositions copy(MecanumDriveWheelPositions positions) {
   }
 
   @Override
-  public MecanumDriveWheelPositions copyInto(
-      MecanumDriveWheelPositions positions, MecanumDriveWheelPositions buffer) {
-    buffer.frontLeftMeters = positions.frontLeftMeters;
-    buffer.frontRightMeters = positions.frontRightMeters;
-    buffer.rearLeftMeters = positions.rearLeftMeters;
-    buffer.rearRightMeters = positions.rearRightMeters;
-    return buffer;
+  public void copyInto(MecanumDriveWheelPositions positions, MecanumDriveWheelPositions output) {
+    output.frontLeftMeters = positions.frontLeftMeters;
+    output.frontRightMeters = positions.frontRightMeters;
+    output.rearLeftMeters = positions.rearLeftMeters;
+    output.rearRightMeters = positions.rearRightMeters;
   }
 
   @Override
diff --git a/wpimath/src/main/java/edu/wpi/first/math/kinematics/Odometry.java b/wpimath/src/main/java/edu/wpi/first/math/kinematics/Odometry.java
index f45fe4e8549..4db2e9651a2 100644
--- a/wpimath/src/main/java/edu/wpi/first/math/kinematics/Odometry.java
+++ b/wpimath/src/main/java/edu/wpi/first/math/kinematics/Odometry.java
@@ -24,7 +24,7 @@ public class Odometry<T> {
 
   private Rotation2d m_gyroOffset;
   private Rotation2d m_previousAngle;
-  private T m_previousWheelPositions;
+  private final T m_previousWheelPositions;
 
   /**
    * Constructs an Odometry object.
@@ -60,7 +60,7 @@ public void resetPosition(Rotation2d gyroAngle, T wheelPositions, Pose2d poseMet
     m_poseMeters = poseMeters;
     m_previousAngle = m_poseMeters.getRotation();
     m_gyroOffset = m_poseMeters.getRotation().minus(gyroAngle);
-    m_previousWheelPositions = m_kinematics.copyInto(wheelPositions, m_previousWheelPositions);
+    m_kinematics.copyInto(wheelPositions, m_previousWheelPositions);
   }
 
   /**
@@ -90,7 +90,7 @@ public Pose2d update(Rotation2d gyroAngle, T wheelPositions) {
 
     var newPose = m_poseMeters.exp(twist);
 
-    m_previousWheelPositions = m_kinematics.copyInto(wheelPositions, m_previousWheelPositions);
+    m_kinematics.copyInto(wheelPositions, m_previousWheelPositions);
     m_previousAngle = angle;
     m_poseMeters = new Pose2d(newPose.getTranslation(), angle);
 
diff --git a/wpimath/src/main/java/edu/wpi/first/math/kinematics/SwerveDriveKinematics.java b/wpimath/src/main/java/edu/wpi/first/math/kinematics/SwerveDriveKinematics.java
index d260c1fc3d8..a25a2bed7da 100644
--- a/wpimath/src/main/java/edu/wpi/first/math/kinematics/SwerveDriveKinematics.java
+++ b/wpimath/src/main/java/edu/wpi/first/math/kinematics/SwerveDriveKinematics.java
@@ -393,16 +393,14 @@ public SwerveModulePosition[] copy(SwerveModulePosition[] positions) {
   }
 
   @Override
-  public SwerveModulePosition[] copyInto(
-      SwerveModulePosition[] positions, SwerveModulePosition[] buffer) {
-    if (positions.length != buffer.length) {
-      return copy(positions);
+  public void copyInto(SwerveModulePosition[] positions, SwerveModulePosition[] output) {
+    if (positions.length != output.length) {
+      throw new IllegalArgumentException("Inconsistent number of modules!");
     }
     for (int i = 0; i < positions.length; ++i) {
-      buffer[i].distanceMeters = positions[i].distanceMeters;
-      buffer[i].angle = positions[i].angle;
+      output[i].distanceMeters = positions[i].distanceMeters;
+      output[i].angle = positions[i].angle;
     }
-    return buffer;
   }
 
   @Override