diff --git a/codan/org.eclipse.cdt.codan.core/src/org/eclipse/cdt/codan/core/builder/CodanBuilder.java b/codan/org.eclipse.cdt.codan.core/src/org/eclipse/cdt/codan/core/builder/CodanBuilder.java
index 683c7b02dda..d12a8cf6652 100644
--- a/codan/org.eclipse.cdt.codan.core/src/org/eclipse/cdt/codan/core/builder/CodanBuilder.java
+++ b/codan/org.eclipse.cdt.codan.core/src/org/eclipse/cdt/codan/core/builder/CodanBuilder.java
@@ -113,6 +113,9 @@ public class CodanBuilder extends IncrementalProjectBuilder {
 	}
 
 	public void reconcileAst(IASTTranslationUnit ast, IProgressMonitor monitor) {
+		if (ast == null)
+			return;
+
 		String filePath = ast.getFilePath();
 		IWorkspace workspace = ResourcesPlugin.getWorkspace();
 		IWorkspaceRoot root = workspace.getRoot();