diff --git a/codan/org.eclipse.cdt.codan.ui.cxx/src/org/eclipse/cdt/codan/internal/ui/cxx/Startup.java b/codan/org.eclipse.cdt.codan.ui.cxx/src/org/eclipse/cdt/codan/internal/ui/cxx/Startup.java
index 237308dfd68..5755b01010e 100644
--- a/codan/org.eclipse.cdt.codan.ui.cxx/src/org/eclipse/cdt/codan/internal/ui/cxx/Startup.java
+++ b/codan/org.eclipse.cdt.codan.ui.cxx/src/org/eclipse/cdt/codan/internal/ui/cxx/Startup.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2009, 2012 Alena Laskavaia 
+ * Copyright (c) 2009, 2012 Alena Laskavaia and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -16,6 +16,7 @@ import org.eclipse.cdt.codan.core.CodanRuntime;
 import org.eclipse.cdt.codan.core.model.CheckerLaunchMode;
 import org.eclipse.cdt.codan.internal.core.CodanBuilder;
 import org.eclipse.cdt.internal.ui.editor.CEditor;
+import org.eclipse.cdt.ui.ICEditor;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.IStatus;
@@ -55,7 +56,7 @@ public class Startup implements IStartup {
 				IWorkbenchWindow active = workbench.getActiveWorkbenchWindow();
 				final IWorkbenchPage page = active.getActivePage();
 				IPartListener2 partListener = new IPartListener2() {
-					CodanCReconciler reconciler = new CodanCReconciler();
+					CodanCReconciler reconciler;
 
 					@Override
 					public void partActivated(IWorkbenchPartReference partRef) {
@@ -68,8 +69,16 @@ public class Startup implements IStartup {
 					@Override
 					public void partOpened(IWorkbenchPartReference partRef) {
 						IWorkbenchPart part = partRef.getPart(false);
-						if (part instanceof CEditor) {
+						// We need to be very careful since this code may be executed in
+						// an invironement where CDT is installed, but is not actively used.
+						// By checking for ICEditor first we avoid loading CEditor class if
+						// the part is not a C/C++ editor. Loading of CEditor class can be very
+						// expensive since it triggers loading of many other classes.
+						if (part instanceof ICEditor && part instanceof CEditor) {
 							CEditor editor = (CEditor) part;
+							if (reconciler == null) {
+								reconciler = new CodanCReconciler();
+							}
 							reconciler.install(editor);
 							IResource resource = (IResource) editor.getEditorInput().getAdapter(IResource.class);
 							if (resource != null) {
@@ -103,7 +112,7 @@ public class Startup implements IStartup {
 					@Override
 					public void partClosed(IWorkbenchPartReference partRef) {
 						IWorkbenchPart part = partRef.getPart(false);
-						if (part instanceof CEditor) {
+						if (reconciler != null && part instanceof ICEditor && part instanceof CEditor) {
 							reconciler.uninstall((CEditor) part);
 						}
 					}
@@ -116,11 +125,11 @@ public class Startup implements IStartup {
 					public void partInputChanged(IWorkbenchPartReference partRef) {
 					}
 				};
+
 				page.addPartListener(partListener);
 				// Check current open editors.
 				IEditorReference[] editorReferences = page.getEditorReferences();
-				for (int i = 0; i < editorReferences.length; i++) {
-					IEditorReference ref = editorReferences[i];
+				for (IEditorReference ref : editorReferences) {
 					partListener.partOpened(ref);
 				}
 			}
diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/editor/CEditor.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/editor/CEditor.java
index cd4398c3813..4057e70b58c 100644
--- a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/editor/CEditor.java
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/editor/CEditor.java
@@ -188,6 +188,7 @@ import org.eclipse.cdt.core.model.ISourceReference;
 import org.eclipse.cdt.core.model.ITranslationUnit;
 import org.eclipse.cdt.core.model.IWorkingCopy;
 import org.eclipse.cdt.ui.CUIPlugin;
+import org.eclipse.cdt.ui.ICEditor;
 import org.eclipse.cdt.ui.IWorkingCopyManager;
 import org.eclipse.cdt.ui.PreferenceConstants;
 import org.eclipse.cdt.ui.actions.GenerateActionGroup;
@@ -241,9 +242,9 @@ import org.eclipse.cdt.internal.ui.viewsupport.SelectionListenerWithASTManager;
 /**
  * C/C++ source editor.
  */
-public class CEditor extends TextEditor implements ISelectionChangedListener, ICReconcilingListener {
+public class CEditor extends TextEditor implements ICEditor, ISelectionChangedListener, ICReconcilingListener {
 	/** Marker used for synchronization from Problems View to the editor on double-click. */
-	private IMarker fSyncProblemsViewMarker = null;
+	private IMarker fSyncProblemsViewMarker;
 
 	/**
 	 * A slightly modified implementation of IGotomarker compared to AbstractDecoratedTextEditor.
diff --git a/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/ui/ICEditor.java b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/ui/ICEditor.java
new file mode 100644
index 00000000000..ddda03cdc2e
--- /dev/null
+++ b/core/org.eclipse.cdt.ui/src/org/eclipse/cdt/ui/ICEditor.java
@@ -0,0 +1,20 @@
+/*******************************************************************************
+ * Copyright (c) 2010 Google, Inc and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ * 	   Sergey Prigogin (Google) - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.cdt.ui;
+
+import org.eclipse.ui.texteditor.ITextEditor;
+
+/**
+ * Marker interface that distinguishes C/C++ editor from other text editors.
+ * @since 5.4
+ */
+public interface ICEditor extends ITextEditor {
+}