diff --git a/qt/org.eclipse.cdt.qt.core/src/org/eclipse/cdt/internal/qt/core/codan/QtSyntaxChecker.java b/qt/org.eclipse.cdt.qt.core/src/org/eclipse/cdt/internal/qt/core/codan/QtSyntaxChecker.java
index b582aeb8047..93a5896ccd2 100644
--- a/qt/org.eclipse.cdt.qt.core/src/org/eclipse/cdt/internal/qt/core/codan/QtSyntaxChecker.java
+++ b/qt/org.eclipse.cdt.qt.core/src/org/eclipse/cdt/internal/qt/core/codan/QtSyntaxChecker.java
@@ -24,6 +24,8 @@ import org.eclipse.cdt.internal.qt.core.QtMethodReference;
 import org.eclipse.cdt.qt.core.QtNature;
 import org.eclipse.cdt.qt.core.QtPlugin;
 import org.eclipse.cdt.qt.core.index.IQMethod;
+import org.eclipse.core.resources.IResource;
+import org.eclipse.core.runtime.OperationCanceledException;
 import org.eclipse.osgi.util.NLS;
 
 /**
@@ -48,6 +50,13 @@ public class QtSyntaxChecker extends AbstractIndexAstChecker implements IChecker
                 CheckerLaunchMode.RUN_ON_DEMAND );
 	}
 
+	@Override
+	public synchronized boolean processResource(IResource resource) throws OperationCanceledException {
+		if (QtNature.hasNature(resource.getProject()))
+			return super.processResource(resource);
+		return false;
+	}
+
 	@Override
 	public void processAst(IASTTranslationUnit ast) {
 		// Run the checker only on Qt-enabled projects.