diff --git a/platform/platform-impl/src/com/intellij/ui/layout/Row.kt b/platform/platform-impl/src/com/intellij/ui/layout/Row.kt
index 6fdc7dd2656f..222ddaea5c98 100644
--- a/platform/platform-impl/src/com/intellij/ui/layout/Row.kt
+++ b/platform/platform-impl/src/com/intellij/ui/layout/Row.kt
@@ -81,18 +81,20 @@ abstract class Row : Cell(), RowBuilder {
 
   /**
    * Shares cell between components.
+   *
+   * @param isFullWidth If true, the cell occupies the full width of the enclosing component.
    */
-  inline fun cell(isVerticalFlow: Boolean = false, init: Cell.() -> Unit) {
-    setCellMode(true, isVerticalFlow)
+  inline fun cell(isVerticalFlow: Boolean = false, isFullWidth: Boolean = false, init: Cell.() -> Unit) {
+    setCellMode(true, isVerticalFlow, isFullWidth)
     init()
-    setCellMode(false, isVerticalFlow)
+    setCellMode(false, isVerticalFlow, isFullWidth)
   }
 
   @PublishedApi
   internal abstract fun createRow(label: String?, buttonGroup: ButtonGroup?): Row
 
   @PublishedApi
-  internal abstract fun setCellMode(value: Boolean, isVerticalFlow: Boolean)
+  internal abstract fun setCellMode(value: Boolean, isVerticalFlow: Boolean, fullWidth: Boolean)
 
   // backward compatibility
   @Deprecated(level = DeprecationLevel.HIDDEN, message = "deprecated")
diff --git a/platform/platform-impl/src/com/intellij/ui/layout/migLayout/MigLayoutRow.kt b/platform/platform-impl/src/com/intellij/ui/layout/migLayout/MigLayoutRow.kt
index b97cbc6e19cd..534a077e2c6f 100644
--- a/platform/platform-impl/src/com/intellij/ui/layout/migLayout/MigLayoutRow.kt
+++ b/platform/platform-impl/src/com/intellij/ui/layout/migLayout/MigLayoutRow.kt
@@ -14,6 +14,7 @@ import com.intellij.ui.layout.*
 import com.intellij.util.SmartList
 import net.miginfocom.layout.BoundSize
 import net.miginfocom.layout.CC
+import net.miginfocom.layout.LayoutUtil
 import java.awt.Component
 import javax.swing.*
 import javax.swing.border.LineBorder
@@ -185,7 +186,7 @@ internal class MigLayoutRow(private val parent: MigLayoutRow?,
   }
 
   // cell mode not tested with "gear" button, wait first user request
-  override fun setCellMode(value: Boolean, isVerticalFlow: Boolean) {
+  override fun setCellMode(value: Boolean, isVerticalFlow: Boolean, fullWidth: Boolean) {
     if (value) {
       assert(componentIndexWhenCellModeWasEnabled == -1)
       componentIndexWhenCellModeWasEnabled = components.size
@@ -198,6 +199,9 @@ internal class MigLayoutRow(private val parent: MigLayoutRow?,
         val component = components.get(firstComponentIndex)
         val cc = componentConstraints.getOrPut(component) { CC() }
         cc.split(components.size - firstComponentIndex)
+        if (fullWidth) {
+          cc.spanX(LayoutUtil.INF)
+        }
         if (isVerticalFlow) {
           cc.flowY()
           // because when vertical buttons placed near scroll pane, it wil be centered by baseline (and baseline not applicable for grow elements, so, will be centered)