diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/dom/PDOMFile.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/dom/PDOMFile.java
index 9ffa8d035c1..21f01d57692 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/dom/PDOMFile.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/dom/PDOMFile.java
@@ -63,7 +63,7 @@ public class PDOMFile implements IIndexFragmentFile {
 	private final PDOMLinkage fLinkage;
 	private final long record;
 	private IIndexFileLocation location;  // No need to make volatile, all fields of IndexFileLocation are final.
-	private ISignificantMacros sigMacros;  // No need to make volatile, all fields of FileContentsKey are either final or volatile.
+	private ISignificantMacros sigMacros;  // No need to make volatile, all fields of SignificantMacros are either final or atomically updated.
 
 	private static final int FIRST_NAME = 0;
 	private static final int FIRST_INCLUDE = FIRST_NAME + Database.PTR_SIZE;