diff --git a/src/plugins/qt4projectmanager/qt4projectconfigwidget.cpp b/src/plugins/qt4projectmanager/qt4projectconfigwidget.cpp
index 44ded3ddec6..96781714567 100644
--- a/src/plugins/qt4projectmanager/qt4projectconfigwidget.cpp
+++ b/src/plugins/qt4projectmanager/qt4projectconfigwidget.cpp
@@ -319,16 +319,28 @@ void Qt4ProjectConfigWidget::updateImportLabel()
         }
     }
 
-    if (targetMatches) {
-        m_ui->importProblemLabel->setVisible(false);
-        m_ui->importWarningLabel->setVisible(false);
+    QString sourceDirectory =
+            QFileInfo(m_buildConfiguration->qt4Target()->qt4Project()->file()->fileName()).absolutePath();
+    if (!sourceDirectory.endsWith('/'))
+        sourceDirectory.append('/');
+    bool invalidBuildDirectory = m_buildConfiguration->shadowBuild()
+                                 && m_buildConfiguration->buildDirectory().startsWith(sourceDirectory);
+
+    if (invalidBuildDirectory) {
+        m_ui->problemLabel->setVisible(true);
+        m_ui->warningLabel->setVisible(true);
+        m_ui->importLabel->setVisible(visible);
+        m_ui->problemLabel->setText(tr("Building in subdirectories of the source directory is not supported by qmake."));
+    } else if (targetMatches) {
+        m_ui->problemLabel->setVisible(false);
+        m_ui->warningLabel->setVisible(false);
         m_ui->importLabel->setVisible(visible);
     } else {
-        m_ui->importWarningLabel->setVisible(visible);
-        m_ui->importProblemLabel->setVisible(visible);
-        m_ui->importProblemLabel->setText(tr("An incompatible build exists in %1, which will be overwritten.",
-                                             "%1 build directory").
-                                          arg(m_ui->shadowBuildDirEdit->path()));
+        m_ui->warningLabel->setVisible(visible);
+        m_ui->problemLabel->setVisible(visible);
+        m_ui->problemLabel->setText(tr("An incompatible build exists in %1, which will be overwritten.",
+                                       "%1 build directory").
+                                    arg(m_ui->shadowBuildDirEdit->path()));
         m_ui->importLabel->setVisible(false);
     }
 }
diff --git a/src/plugins/qt4projectmanager/qt4projectconfigwidget.ui b/src/plugins/qt4projectmanager/qt4projectconfigwidget.ui
index 81cb23e9a03..bb0acd3a161 100644
--- a/src/plugins/qt4projectmanager/qt4projectconfigwidget.ui
+++ b/src/plugins/qt4projectmanager/qt4projectconfigwidget.ui
@@ -6,7 +6,7 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>487</width>
+    <width>712</width>
     <height>194</height>
    </rect>
   </property>
@@ -138,16 +138,16 @@
       </widget>
      </item>
      <item>
-      <widget class="QLabel" name="importWarningLabel">
+      <widget class="QLabel" name="warningLabel">
        <property name="pixmap">
         <pixmap resource="../projectexplorer/projectexplorer.qrc">:/projectexplorer/images/compile_warning.png</pixmap>
        </property>
       </widget>
      </item>
      <item>
-      <widget class="QLabel" name="importProblemLabel">
+      <widget class="QLabel" name="problemLabel">
        <property name="text">
-        <string>The Qt Version about to be imported does not support this target.</string>
+        <string>problemLabel</string>
        </property>
       </widget>
      </item>