diff --git a/pom.xml b/pom.xml
index 07532c6..d7bff18 100644
--- a/pom.xml
+++ b/pom.xml
@@ -272,7 +272,7 @@
                         <configuration>
                             <quiet>true</quiet>
                             <doclint>none</doclint>
-                            <failOnWarnings>false</failOnWarnings>
+                            <failOnWarnings>true</failOnWarnings>
                             <links>
                                 <link>https://javadoc.io/doc/com.vaadin/vaadin-platform-javadoc/${vaadin.version}</link>
                             </links>
diff --git a/src/main/java/com/flowingcode/vaadin/addons/twincolgrid/LegacyTwinColGrid.java b/src/main/java/com/flowingcode/vaadin/addons/twincolgrid/LegacyTwinColGrid.java
index 31c5d4d..2ef114f 100644
--- a/src/main/java/com/flowingcode/vaadin/addons/twincolgrid/LegacyTwinColGrid.java
+++ b/src/main/java/com/flowingcode/vaadin/addons/twincolgrid/LegacyTwinColGrid.java
@@ -89,8 +89,8 @@ public LegacyTwinColGrid(String caption) {
    *
    * @param dataProvider the data provider, not {@code null}
    * @param caption the component caption
-   * @deprecated Use {@link #TwinColGrid()} and {@link #setDataProvider(ListDataProvider)}, {@link
-   *     #setCaption(String)}
+   * @deprecated Use {@link TwinColGrid#TwinColGrid()} and
+   *             {@link #setDataProvider(ListDataProvider)}, {@link #setCaption(String)}
    */
   @Deprecated
   @SuppressWarnings("unchecked")
@@ -147,7 +147,8 @@ public LegacyTwinColGrid(
    *
    * @param caption the caption to set, can be {@code null}
    * @param options the options, cannot be {@code null}
-   * @deprecated Use {@link #TwinColGrid(Collection)} and {{@link #setCaption(String)}
+   * @deprecated Use {@link TwinColGrid#TwinColGrid(Collection)} and
+   *             {{@link TwinColGrid#setCaption(String)}
    */
   @Deprecated
   @SuppressWarnings("unchecked")
@@ -338,7 +339,7 @@ public LegacyTwinColGrid<T> addSortableColumn(
    * @param itemLabelGenerator the value provider
    * @param comparator the in-memory comparator
    * @param header the column header
-   * @param header the column key
+   * @param key the column key
    * @return this instance
    */
   @Deprecated
diff --git a/src/main/java/com/flowingcode/vaadin/addons/twincolgrid/TwinColGrid.java b/src/main/java/com/flowingcode/vaadin/addons/twincolgrid/TwinColGrid.java
index 4580636..a47e706 100644
--- a/src/main/java/com/flowingcode/vaadin/addons/twincolgrid/TwinColGrid.java
+++ b/src/main/java/com/flowingcode/vaadin/addons/twincolgrid/TwinColGrid.java
@@ -251,7 +251,7 @@ private void initMoveItemsByDoubleClick() {
   /**
    * Sets the component caption.
    *
-   * @param captinText the component caption.
+   * @param captionText the component caption.
    */
   public void setCaption(String captionText) {
     if (captionText != null) {
@@ -282,7 +282,7 @@ public String getCaption() {
    * Sets orientation for TwinColGridComponent
    *
    * @param orientation
-   * @return
+   * @return this instance for method chaining.
    */
   public TwinColGrid<T> withOrientation(Orientation orientation) {
     if (this.orientation != orientation) {
@@ -336,7 +336,7 @@ private Component createContainerLayout() {
 
   private String getLayoutId() {
     return Optional.ofNullable(layoutId).orElseGet(()->{
-      return this.layoutId = "twincol-" + UUID.randomUUID();
+      return layoutId = "twincol-" + UUID.randomUUID();
     });
   }
 
diff --git a/src/main/java/com/flowingcode/vaadin/addons/twincolgrid/TwinColumn.java b/src/main/java/com/flowingcode/vaadin/addons/twincolgrid/TwinColumn.java
index 8064d7a..38eba89 100644
--- a/src/main/java/com/flowingcode/vaadin/addons/twincolgrid/TwinColumn.java
+++ b/src/main/java/com/flowingcode/vaadin/addons/twincolgrid/TwinColumn.java
@@ -199,9 +199,9 @@ public TwinColumn<T> setFooter(String labelText) {
    *        header of each column
    * @return this instance, for method chaining
    */
-  public TwinColumn<T> setHeader(Supplier<Component> footerComponentSupplier) {
-    availableColumn.setHeader(footerComponentSupplier.get());
-    selectionColumn.setHeader(footerComponentSupplier.get());
+  public TwinColumn<T> setHeader(Supplier<Component> headerComponentSupplier) {
+    availableColumn.setHeader(headerComponentSupplier.get());
+    selectionColumn.setHeader(headerComponentSupplier.get());
     return this;
   }
 
@@ -210,7 +210,7 @@ public TwinColumn<T> setHeader(Supplier<Component> footerComponentSupplier) {
    *
    * @see Column#setFooter(String)
    *
-   * @param footerComponentSuppleir a supplier that instantiates the component to be used in the
+   * @param footerComponentSupplier a supplier that instantiates the component to be used in the
    *        footer of each column
    * @return this instance, for method chaining
    */