diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/PDOMWriter.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/PDOMWriter.java
index 844a33faffe..4ca5d94b10c 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/PDOMWriter.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/PDOMWriter.java
@@ -334,6 +334,7 @@ public abstract class PDOMWriter implements IPDOMASTProcessor {
 						}
 					}
 				} catch (OperationCanceledException e) {
+					throw e;
 				} catch (RuntimeException | StackOverflowError | AssertionError e) {
 					th= e;
 				} finally {