diff --git a/dev/core/src/com/google/gwt/dev/jjs/UnifiedAst.java b/dev/core/src/com/google/gwt/dev/jjs/UnifiedAst.java
index 79deb6d..d0c521c7 100644
--- a/dev/core/src/com/google/gwt/dev/jjs/UnifiedAst.java
+++ b/dev/core/src/com/google/gwt/dev/jjs/UnifiedAst.java
@@ -185,7 +185,7 @@
       diskCache.transferToStream(serializedAstToken, stream);
     } else if (initialAst != null) {
       // Serialize into raw bytes.
-      Util.writeObjectToStream(stream, stream);
+      Util.writeObjectToStream(stream, initialAst);
     } else {
       throw new IllegalStateException(
           "No serialized AST was cached and AST was already consumed.");