diff --git a/platform/platform-impl/src/com/intellij/ide/ui/laf/darcula/ui/DarculaComboBoxUI.java b/platform/platform-impl/src/com/intellij/ide/ui/laf/darcula/ui/DarculaComboBoxUI.java
index 763d4cf21c0a..6fcf0a43effa 100644
--- a/platform/platform-impl/src/com/intellij/ide/ui/laf/darcula/ui/DarculaComboBoxUI.java
+++ b/platform/platform-impl/src/com/intellij/ide/ui/laf/darcula/ui/DarculaComboBoxUI.java
@@ -397,7 +397,7 @@ public class DarculaComboBoxUI extends BasicComboBoxUI implements Border, ErrorB
     Insets i = getInsets();
     Dimension abSize = arrowButton.getPreferredSize();
 
-    if (isCompact(comboBox)) {
+    if (isCompact(comboBox) && size != null) {
       JBInsets.removeFrom(size, padding); // don't count paddings in compact mode
     }
 
@@ -405,8 +405,11 @@ public class DarculaComboBoxUI extends BasicComboBoxUI implements Border, ErrorB
     int editorWidth = editorSize != null ? editorSize.width + i.left + padding.left + padding.right : 0;
     editorWidth = Math.max(editorWidth, MINIMUM_WIDTH.get() + i.left);
 
-    int width = Math.max(editorWidth + abSize.width, size.width + padding.left);
-    int height = Math.max(Math.max(editorHeight, Math.max(abSize.height, size.height)),
+    int width = size != null ? size.width : 0;
+    int height = size != null ? size.height : 0;
+
+    width = Math.max(editorWidth + abSize.width, width + padding.left);
+    height = Math.max(Math.max(editorHeight, Math.max(abSize.height, height)),
                           (isCompact(comboBox) ? COMPACT_HEIGHT.get() : MINIMUM_HEIGHT.get()) + i.top + i.bottom);
 
     return new Dimension(width, height);
diff --git a/platform/platform-impl/src/com/intellij/ide/ui/laf/intellij/MacIntelliJComboBoxUI.java b/platform/platform-impl/src/com/intellij/ide/ui/laf/intellij/MacIntelliJComboBoxUI.java
index c707915d4b41..6724853e5136 100644
--- a/platform/platform-impl/src/com/intellij/ide/ui/laf/intellij/MacIntelliJComboBoxUI.java
+++ b/platform/platform-impl/src/com/intellij/ide/ui/laf/intellij/MacIntelliJComboBoxUI.java
@@ -84,8 +84,13 @@ public class MacIntelliJComboBoxUI extends DarculaComboBoxUI {
     int editorWidth = editorSize != null ? editorSize.width + i.left + padding.left + padding.right : 0;
     editorWidth = Math.max(editorWidth, MINIMUM_WIDTH.get() + i.left);
 
-    return new Dimension(Math.max(size.width + padding.left, editorWidth + iconWidth),
-                         Math.max(Math.max(iconHeight, size.height), editorHeight));
+    int width = size != null ? size.width : 0;
+    int height = size != null ? size.height : 0;
+
+    width = Math.max(width + padding.left, editorWidth + iconWidth);
+    height = Math.max(Math.max(iconHeight, height), editorHeight);
+
+    return new Dimension(width, height);
   }
 
   @Override
diff --git a/platform/platform-impl/src/com/intellij/ide/ui/laf/intellij/WinIntelliJComboBoxUI.java b/platform/platform-impl/src/com/intellij/ide/ui/laf/intellij/WinIntelliJComboBoxUI.java
index f9163e0ec6d2..faa9b3ff02c2 100644
--- a/platform/platform-impl/src/com/intellij/ide/ui/laf/intellij/WinIntelliJComboBoxUI.java
+++ b/platform/platform-impl/src/com/intellij/ide/ui/laf/intellij/WinIntelliJComboBoxUI.java
@@ -447,8 +447,13 @@ public class WinIntelliJComboBoxUI extends DarculaComboBoxUI {
     int editorWidth = editorSize != null ? editorSize.width + i.left + padding.left + padding.right : 0;
     editorWidth = Math.max(editorWidth, MINIMUM_WIDTH.get() + i.left);
 
-    return new Dimension(Math.max(editorWidth + ARROW_BUTTON_SIZE.width, size.width + padding.left),
-                         Math.max(ARROW_BUTTON_SIZE.height, Math.max(editorHeight, size.height)));
+    int width = size != null ? size.width : 0;
+    int height = size != null ? size.height : 0;
+
+    width = Math.max(editorWidth + ARROW_BUTTON_SIZE.width, width + padding.left);
+    height = Math.max(ARROW_BUTTON_SIZE.height, Math.max(editorHeight, height));
+
+    return new Dimension(width, height);
   }
 
   @Override