diff --git a/src/plugins/coreplugin/sidebar.cpp b/src/plugins/coreplugin/sidebar.cpp
index 4705dc9be8d7be31541b4074baefcef049d8ecf4..a89720c240238a60437b11a0291f83ea4d77f070 100644
--- a/src/plugins/coreplugin/sidebar.cpp
+++ b/src/plugins/coreplugin/sidebar.cpp
@@ -288,9 +288,9 @@ void SideBarWidget::setCurrentItem(const QString &title)
         int idx = m_comboBox->findText(title);
         if (idx < 0)
             idx = 0;
-        m_comboBox->blockSignals(true);
+        bool blocked = m_comboBox->blockSignals(true);
         m_comboBox->setCurrentIndex(idx);
-        m_comboBox->blockSignals(false);
+        m_comboBox->blockSignals(blocked);
     }
 
     SideBarItem *item = m_sideBar->item(title);
@@ -307,7 +307,7 @@ void SideBarWidget::setCurrentItem(const QString &title)
 
 void SideBarWidget::updateAvailableItems()
 {
-    m_comboBox->blockSignals(true);
+    bool blocked = m_comboBox->blockSignals(true);
     QString current = m_comboBox->currentText();
     m_comboBox->clear();
     QStringList itms = m_sideBar->availableItems();
@@ -320,7 +320,7 @@ void SideBarWidget::updateAvailableItems()
         idx = 0;
     m_comboBox->setCurrentIndex(idx);
     m_splitButton->setEnabled(itms.count() > 1);
-    m_comboBox->blockSignals(false);
+    m_comboBox->blockSignals(blocked);
 }
 
 void SideBarWidget::removeCurrentItem()
diff --git a/src/plugins/debugger/gdb/plaingdbadapter.cpp b/src/plugins/debugger/gdb/plaingdbadapter.cpp
index 683b7ccddeab91561575aa727a244c26b7e71ea5..a65381920b6b1ed4735371aab4d039e79843e7ef 100644
--- a/src/plugins/debugger/gdb/plaingdbadapter.cpp
+++ b/src/plugins/debugger/gdb/plaingdbadapter.cpp
@@ -337,9 +337,9 @@ void PlainGdbAdapter::emitAdapterStartFailed(const QString &msg)
 {
     //  QMessageBox::critical(mainWindow(), tr("Debugger Startup Failure"),
     //    tr("Cannot start debugger: %1").arg(m_gdbAdapter->errorString()));
-    m_stubProc.blockSignals(true);
+    bool blocked = m_stubProc.blockSignals(true);
     m_stubProc.stop();
-    m_stubProc.blockSignals(false);
+    m_stubProc.blockSignals(blocked);
     emit adapterStartFailed(msg);
 }
 
diff --git a/src/plugins/help/helpplugin.cpp b/src/plugins/help/helpplugin.cpp
index d05384920b4280e4740b1da2ad6ca0936494cb6b..8421dca38d269cb2c2e46fc1a360aafe341dda8a 100644
--- a/src/plugins/help/helpplugin.cpp
+++ b/src/plugins/help/helpplugin.cpp
@@ -633,9 +633,9 @@ void HelpPlugin::extensionsInitialized()
             hc.addCustomFilter(tr("Unfiltered"), QStringList());
             hc.setCustomValue(key, 1);
         }
-        m_helpEngine->blockSignals(true);
+        bool blocked = m_helpEngine->blockSignals(true);
         m_helpEngine->setCurrentFilter(tr("Unfiltered"));
-        m_helpEngine->blockSignals(false);
+        m_helpEngine->blockSignals(blocked);
         needsSetup = true;
     }
 
diff --git a/src/plugins/projectexplorer/buildsettingspropertiespage.cpp b/src/plugins/projectexplorer/buildsettingspropertiespage.cpp
index b6fe770d543112d287fb2ee0088e4fb92237f20c..82e187367b6a11105a34ee1e448236a8c63c900e 100644
--- a/src/plugins/projectexplorer/buildsettingspropertiespage.cpp
+++ b/src/plugins/projectexplorer/buildsettingspropertiespage.cpp
@@ -220,7 +220,7 @@ void BuildSettingsWidget::updateBuildSettings()
     // TODO save position, entry from combbox
 
     // Delete old tree items
-    m_buildConfigurationComboBox->blockSignals(true);
+    bool blocked = m_buildConfigurationComboBox->blockSignals(true);
     m_buildConfigurationComboBox->clear();
     m_subWidgets->clear();
 
@@ -245,7 +245,7 @@ void BuildSettingsWidget::updateBuildSettings()
             m_buildConfigurationComboBox->setCurrentIndex(m_buildConfigurationComboBox->count() - 1);
     }
 
-    m_buildConfigurationComboBox->blockSignals(false);
+    m_buildConfigurationComboBox->blockSignals(blocked);
 
     // TODO Restore position, entry from combbox
     // TODO? select entry from combobox ?