diff --git a/platform/diff-api/src/com/intellij/diff/comparison/DiffTooBigException.java b/platform/diff-api/src/com/intellij/diff/comparison/DiffTooBigException.java
index fca771012ad9..9e3bedc3a293 100644
--- a/platform/diff-api/src/com/intellij/diff/comparison/DiffTooBigException.java
+++ b/platform/diff-api/src/com/intellij/diff/comparison/DiffTooBigException.java
@@ -23,11 +23,6 @@ public class DiffTooBigException extends ProcessCanceledException {
   public DiffTooBigException() {
   }
 
-  public DiffTooBigException(Throwable cause) {
-    super(cause);
-  }
-
-
   @Override
   public String getMessage() {
     return MESSAGE;
diff --git a/platform/util/src/com/intellij/openapi/progress/ProcessCanceledException.java b/platform/util/src/com/intellij/openapi/progress/ProcessCanceledException.java
index f19097268004..598fd86f2c61 100644
--- a/platform/util/src/com/intellij/openapi/progress/ProcessCanceledException.java
+++ b/platform/util/src/com/intellij/openapi/progress/ProcessCanceledException.java
@@ -23,5 +23,8 @@ public class ProcessCanceledException extends RuntimeException implements Contro
 
   public ProcessCanceledException(@NotNull Throwable cause) {
     super(cause);
+    if (cause instanceof ProcessCanceledException) {
+      throw new IllegalArgumentException("Must not self-wrap ProcessCanceledException: " + cause);
+    }
   }
 }
diff --git a/platform/util/src/com/intellij/openapi/util/objectTree/ObjectNode.java b/platform/util/src/com/intellij/openapi/util/objectTree/ObjectNode.java
index 118f20c3de3e..07830ad6d335 100644
--- a/platform/util/src/com/intellij/openapi/util/objectTree/ObjectNode.java
+++ b/platform/util/src/com/intellij/openapi/util/objectTree/ObjectNode.java
@@ -133,7 +133,7 @@ final class ObjectNode<T> {
           myTree.fireExecuted(myObject);
         }
         catch (ProcessCanceledException e) {
-          throw new ProcessCanceledException(e);
+          throw e;
         }
         catch (Throwable e) {
           LOG.error(e);