diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -112,10 +112,12 @@
 # Turn off missing-field-initializers warning for GCC to avoid noise from false positives with empty {}
 # See discussion: http://mail.kde.org/pipermail/kdevelop-devel/2014-February/046910.html
 add_compile_flag_if_supported(-Wno-missing-field-initializers)
+add_compile_flag_if_supported(-Werror=switch)
 add_compile_flag_if_supported(-Werror=undefined-bool-conversion)
 add_compile_flag_if_supported(-Werror=tautological-undefined-compare)
 if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
     add_compile_flag_if_supported(-Wdocumentation)
+    add_compile_flag_if_supported(-Wcovered-switch-default)
     # This warning is triggered by every call to qCDebug()
     add_compile_flag_if_supported(-Wno-gnu-zero-variadic-macro-arguments)
 endif()
diff --git a/kdevplatform/language/duchain/navigation/abstractdeclarationnavigationcontext.cpp b/kdevplatform/language/duchain/navigation/abstractdeclarationnavigationcontext.cpp
--- a/kdevplatform/language/duchain/navigation/abstractdeclarationnavigationcontext.cpp
+++ b/kdevplatform/language/duchain/navigation/abstractdeclarationnavigationcontext.cpp
@@ -568,9 +568,6 @@
       case ClassDeclarationData::Trait:
         modifyHtml() += QStringLiteral("trait ");
         break;
-      default:
-        modifyHtml() += QStringLiteral("<unknown type> ");
-        break;
     }
     eventuallyMakeTypeLinks( klass.cast<AbstractType>() );
 
diff --git a/kdevplatform/outputview/outputexecutejob.cpp b/kdevplatform/outputview/outputexecutejob.cpp
--- a/kdevplatform/outputview/outputexecutejob.cpp
+++ b/kdevplatform/outputview/outputexecutejob.cpp
@@ -344,7 +344,6 @@
             errorValue = i18n("Waiting for the process has timed out");
             break;
 
-        default:
         case QProcess::UnknownError:
             errorValue = i18n("Exit code %1", d->m_process->exitCode());
             break;
diff --git a/kdevplatform/outputview/tests/test_filteringstrategy.cpp b/kdevplatform/outputview/tests/test_filteringstrategy.cpp
--- a/kdevplatform/outputview/tests/test_filteringstrategy.cpp
+++ b/kdevplatform/outputview/tests/test_filteringstrategy.cpp
@@ -63,9 +63,8 @@
             return QTest::newRow(QString(QLatin1String(dataTag)+QLatin1String("-windows-ns")).toUtf8().constData());
         case WindowsFilePathWithSpaces:
             return QTest::newRow(QString(QLatin1String(dataTag)+QLatin1String("-windows-ws")).toUtf8().constData());
-        default:
-            return QTest::newRow(dataTag);
     }
+    Q_UNREACHABLE();
 }
 
 }
diff --git a/kdevplatform/outputview/tests/testlinebuilderfunctions.h b/kdevplatform/outputview/tests/testlinebuilderfunctions.h
--- a/kdevplatform/outputview/tests/testlinebuilderfunctions.h
+++ b/kdevplatform/outputview/tests/testlinebuilderfunctions.h
@@ -50,10 +50,8 @@
             return QStringLiteral("/some/path/to/a/project");
         case UnixFilePathWithSpaces:
             return QStringLiteral("/some/path with spaces/to/a/project");
-        default:
-            Q_ASSERT(0);
-            return QStringLiteral("/we/should/never/end/up/here");
     }
+    Q_UNREACHABLE();
 }
 
 QString buildCppCheckErrorLine(TestPathType pathType = UnixFilePathNoSpaces)
diff --git a/plugins/debuggercommon/midebugger.cpp b/plugins/debuggercommon/midebugger.cpp
--- a/plugins/debuggercommon/midebugger.cpp
+++ b/plugins/debuggercommon/midebugger.cpp
@@ -281,9 +281,6 @@
                 // On-going status information about progress of a slow operation; may be ignored
                 break;
             }
-
-            default:
-                Q_ASSERT(false);
             }
             break;
         }
diff --git a/plugins/debuggercommon/widgets/disassemblewidget.cpp b/plugins/debuggercommon/widgets/disassemblewidget.cpp
--- a/plugins/debuggercommon/widgets/disassemblewidget.cpp
+++ b/plugins/debuggercommon/widgets/disassemblewidget.cpp
@@ -134,7 +134,6 @@
 {
     switch(flavor)
     {
-    default:
     case DisassemblyFlavorUnknown:
         m_disassemblyFlavorAtt->setChecked(false);
         m_disassemblyFlavorIntel->setChecked(false);
diff --git a/plugins/documentview/kdevdocumentmodel.cpp b/plugins/documentview/kdevdocumentmodel.cpp
--- a/plugins/documentview/kdevdocumentmodel.cpp
+++ b/plugins/documentview/kdevdocumentmodel.cpp
@@ -45,9 +45,8 @@
         return QIcon::fromTheme(QStringLiteral("document-revert"));
     case IDocument::DirtyAndModified:
         return QIcon::fromTheme(QStringLiteral("edit-delete"));
-    default:
-        return QIcon();
     }
+    Q_UNREACHABLE();
 }
 
 IDocument::DocumentState KDevDocumentItem::documentState() const
diff --git a/plugins/filetemplates/overridespage.cpp b/plugins/filetemplates/overridespage.cpp
--- a/plugins/filetemplates/overridespage.cpp
+++ b/plugins/filetemplates/overridespage.cpp
@@ -51,11 +51,8 @@
         return i18n("Protected");
     case Declaration::Private:
         return i18n("Private");
-    default:
-        qCritical("Unexpected value for Declaration::AccessPolicy: %d", accessPolicy);
-        Q_ASSERT(false);
-        return QString();
     }
+    Q_UNREACHABLE();
 }
 
 static QString functionPropertiesToString(ClassFunctionDeclaration* decl)
diff --git a/plugins/testview/testview.cpp b/plugins/testview/testview.cpp
--- a/plugins/testview/testview.cpp
+++ b/plugins/testview/testview.cpp
@@ -217,10 +217,8 @@
 
         case TestResult::Error:
             return QIcon::fromTheme(QStringLiteral("dialog-cancel"));
-
-        default:
-            return QIcon::fromTheme(QLatin1String(""));
     }
+    Q_UNREACHABLE();
 }
 
 QStandardItem* TestView::itemForSuite(ITestSuite* suite)