--- a/truffle/com.oracle.truffle.api.object/src/com/oracle/truffle/api/object/DynamicObject.java	Sat Sep 12 22:37:38 2015 +0200
+++ b/truffle/com.oracle.truffle.api.object/src/com/oracle/truffle/api/object/DynamicObject.java	Sat Sep 12 22:47:16 2015 +0200
@@ -103,24 +103,6 @@
     public abstract void define(Object key, Object value, int flags, LocationFactory locationFactory);
 
     /**
-     * Change property flags.
-     *
-     * @param key property identifier
-     * @param newFlags flags to be set
-     * @return {@code true} if successful or {@code false} if property not found
-     */
-    public abstract boolean changeFlags(Object key, int newFlags);
-
-    /**
-     * Change property flags.
-     *
-     * @param key property identifier
-     * @param flagsUpdateFunction function updating old flags to new flags
-     * @return {@code true} if successful or {@code false} if property not found
-     */
-    public abstract boolean changeFlags(Object key, FlagsFunction flagsUpdateFunction);
-
-    /**
      * Delete property.
      *
      * @param key property identifier
@@ -167,14 +149,4 @@
      * @param currentShape the object's current shape (must equal {@link #getShape()})
      */
     public abstract DynamicObject copy(Shape currentShape);
-
-    /**
-     * Represents an operation on a single {@code int}-valued operand that produces an {@code int}
-     * -valued result.
-     *
-     * For Java 7 compatibility (equivalent to IntUnaryOperator).
-     */
-    public interface FlagsFunction {
-        int apply(int t);
-    }
 }

--- a/truffle/com.oracle.truffle.object/src/com/oracle/truffle/object/DynamicObjectImpl.java	Sat Sep 12 22:37:38 2015 +0200
+++ b/truffle/com.oracle.truffle.object/src/com/oracle/truffle/object/DynamicObjectImpl.java	Sat Sep 12 22:47:16 2015 +0200
@@ -184,7 +184,6 @@
         }
     }
 
-    @Override
     @TruffleBoundary
     public boolean changeFlags(Object id, int newFlags) {
         Shape oldShape = getShape();
@@ -201,24 +200,6 @@
         }
     }
 
-    @Override
-    @TruffleBoundary
-    public boolean changeFlags(Object id, FlagsFunction updateFunction) {
-        Shape oldShape = getShape();
-        Property existing = oldShape.getProperty(id);
-        if (existing != null) {
-            int newFlags = updateFunction.apply(existing.getFlags());
-            if (existing.getFlags() != newFlags) {
-                Property newProperty = existing.copyWithFlags(newFlags);
-                Shape newShape = oldShape.replaceProperty(existing, newProperty);
-                this.setShape(newShape);
-            }
-            return true;
-        } else {
-            return false;
-        }
-    }
-
     public String debugDump(int level) {
         return debugDump(0, level);
     }