diff --git a/core/src/main/python/deploy.py b/core/src/main/python/deploy.py
index 79a2b8cb9..80dd3c00f 100644
--- a/core/src/main/python/deploy.py
+++ b/core/src/main/python/deploy.py
@@ -16,7 +16,6 @@
 from oracle.weblogic.deploy.exception import BundleAwareException
 from oracle.weblogic.deploy.util import CLAException
 from oracle.weblogic.deploy.util import FileUtils
-from oracle.weblogic.deploy.util import PyWLSTException
 from oracle.weblogic.deploy.util import TranslateException
 from oracle.weblogic.deploy.util import VariableException
 from oracle.weblogic.deploy.util import WebLogicDeployToolingVersion
@@ -283,10 +282,7 @@ def __deploy_online(model, model_context, aliases):
         deployer_utils.ensure_no_uncommitted_changes_or_edit_sessions()
         __wlst_helper.edit()
         __wlst_helper.start_edit()
-    except PyWLSTException, pwe:
-        ex = exception_helper.create_deploy_exception('WLSDPLY-09006', _program_name, admin_url,
-                                                      pwe.getLocalizedMessage(), error=pwe)
-        __logger.throwing(ex, class_name=_class_name, method_name=_method_name)
+    except BundleAwareException, ex:
         raise ex
 
     __logger.info("WLSDPLY-09007", admin_url, method_name=_method_name, class_name=_class_name)
@@ -300,9 +296,7 @@ def __deploy_online(model, model_context, aliases):
     try:
         __wlst_helper.save()
         __wlst_helper.activate()
-    except PyWLSTException, pwe:
-        ex = exception_helper.create_deploy_exception('WLSDPLY-09008', pwe.getLocalizedMessage(), error=pwe)
-        __logger.throwing(ex, class_name=_class_name, method_name=_method_name)
+    except BundleAwareException, ex:
         __release_edit_session_and_disconnect()
         raise ex
 
@@ -310,10 +304,10 @@ def __deploy_online(model, model_context, aliases):
 
     try:
         __wlst_helper.disconnect()
-    except PyWLSTException, pwe:
+    except BundleAwareException, ex:
         # All the changes are made and active so don't raise an error that causes the program
         # to indicate a failure...just log the error since the process is going to exit anyway.
-        __logger.warning('WLSDPLY-09009', _program_name, pwe.getLocalizedMessage(), error=pwe,
+        __logger.warning('WLSDPLY-09009', _program_name, ex.getLocalizedMessage(), error=ex,
                          class_name=_class_name, method_name=_method_name)
     return
 
@@ -357,6 +351,7 @@ def __release_edit_session_and_disconnect():
     """
     _method_name = '__release_edit_session_and_disconnect'
     try:
+        __wlst_helper.undo()
         __wlst_helper.stop_edit()
         __wlst_helper.disconnect()
     except BundleAwareException, ex:
@@ -374,10 +369,10 @@ def __close_domain_on_error():
     _method_name = '__close_domain_on_error'
     try:
         __wlst_helper.close_domain()
-    except PyWLSTException, pwe:
+    except BundleAwareException, ex:
         # This method is only used for cleanup after an error so don't mask
         # the original problem by throwing yet another exception...
-        __logger.warning('WLSDPLY-09013', pwe.getLocalizedMessage(), error=pwe,
+        __logger.warning('WLSDPLY-09013', ex.getLocalizedMessage(), error=ex,
                          class_name=_class_name, method_name=_method_name)
     return
 
@@ -478,6 +473,7 @@ def main(args):
     __clean_up_temp_files()
     return
 
+
 if __name__ == "main":
     WebLogicDeployToolingVersion.logVersionInfo(_program_name)
     main(sys.argv)
diff --git a/core/src/main/python/update.py b/core/src/main/python/update.py
index 1bf036cae..1b765cb05 100644
--- a/core/src/main/python/update.py
+++ b/core/src/main/python/update.py
@@ -16,7 +16,6 @@
 from oracle.weblogic.deploy.exception import BundleAwareException
 from oracle.weblogic.deploy.util import CLAException
 from oracle.weblogic.deploy.util import FileUtils
-from oracle.weblogic.deploy.util import PyWLSTException
 from oracle.weblogic.deploy.util import TranslateException
 from oracle.weblogic.deploy.util import VariableException
 from oracle.weblogic.deploy.util import WebLogicDeployToolingVersion
@@ -294,10 +293,7 @@ def __update_online(model, model_context, aliases):
         deployer_utils.ensure_no_uncommitted_changes_or_edit_sessions()
         __wlst_helper.edit()
         __wlst_helper.start_edit()
-    except PyWLSTException, pwe:
-        ex = exception_helper.create_deploy_exception('WLSDPLY-09006', _program_name, admin_url,
-                                                      pwe.getLocalizedMessage(), error=pwe)
-        __logger.throwing(ex, class_name=_class_name, method_name=_method_name)
+    except BundleAwareException, ex:
         raise ex
 
     __logger.info("WLSDPLY-09007", admin_url, method_name=_method_name, class_name=_class_name)
@@ -314,9 +310,7 @@ def __update_online(model, model_context, aliases):
     try:
         __wlst_helper.save()
         __wlst_helper.activate()
-    except PyWLSTException, pwe:
-        ex = exception_helper.create_deploy_exception('WLSDPLY-09008', pwe.getLocalizedMessage(), error=pwe)
-        __logger.throwing(ex, class_name=_class_name, method_name=_method_name)
+    except BundleAwareException, ex:
         __release_edit_session_and_disconnect()
         raise ex
 
@@ -324,10 +318,10 @@ def __update_online(model, model_context, aliases):
 
     try:
         __wlst_helper.disconnect()
-    except PyWLSTException, pwe:
+    except BundleAwareException, ex:
         # All the changes are made and active so don't raise an error that causes the program
         # to indicate a failure...just log the error since the process is going to exit anyway.
-        __logger.warning('WLSDPLY-09009', _program_name, pwe.getLocalizedMessage(), error=pwe,
+        __logger.warning('WLSDPLY-09009', _program_name, ex.getLocalizedMessage(), error=ex,
                          class_name=_class_name, method_name=_method_name)
     return
 
@@ -374,6 +368,7 @@ def __release_edit_session_and_disconnect():
     """
     _method_name = '__release_edit_session_and_disconnect'
     try:
+        __wlst_helper.undo()
         __wlst_helper.stop_edit()
         __wlst_helper.disconnect()
     except BundleAwareException, ex:
@@ -391,10 +386,10 @@ def __close_domain_on_error():
     _method_name = '__close_domain_on_error'
     try:
         __wlst_helper.close_domain()
-    except PyWLSTException, pwe:
+    except BundleAwareException, ex:
         # This method is only used for cleanup after an error so don't mask
         # the original problem by throwing yet another exception...
-        __logger.warning('WLSDPLY-09013', pwe.getLocalizedMessage(), error=pwe,
+        __logger.warning('WLSDPLY-09013', ex.getLocalizedMessage(), error=ex,
                          class_name=_class_name, method_name=_method_name)
     return
 
diff --git a/core/src/main/python/wlsdeploy/tool/util/wlst_helper.py b/core/src/main/python/wlsdeploy/tool/util/wlst_helper.py
index 28452b344..a2d434089 100644
--- a/core/src/main/python/wlsdeploy/tool/util/wlst_helper.py
+++ b/core/src/main/python/wlsdeploy/tool/util/wlst_helper.py
@@ -520,6 +520,22 @@ def stop_edit(self):
             raise ex
         return
 
+    def undo(self):
+        """
+        Revert all unsaved or unactivated edits.
+        :raises: BundleAwareException of the specified type: if an error occurs
+        """
+        _method_name = 'undo'
+
+        try:
+            wlst_helper.undo()
+        except PyWLSTException, pwe:
+            ex = exception_helper.create_exception(self.__exception_type, 'WLSDPLY-19142',
+                                                   pwe.getLocalizedMessage(), error=pwe)
+            self.__logger.throwing(ex, class_name=self.__class_name, method_name=_method_name)
+            raise ex
+        return
+
     def save(self):
         """
         Save the outstanding Weblogic Server configuration changes for the current edit session.
diff --git a/core/src/main/python/wlsdeploy/util/wlst_helper.py b/core/src/main/python/wlsdeploy/util/wlst_helper.py
index df21ad365..6191f4437 100644
--- a/core/src/main/python/wlsdeploy/util/wlst_helper.py
+++ b/core/src/main/python/wlsdeploy/util/wlst_helper.py
@@ -692,6 +692,23 @@ def stop_edit():
     _logger.exiting(class_name=_class_name, method_name=_method_name)
 
 
+def undo():
+    """
+    Revert all unsaved or unactivated edits.
+    :raises: PyWLSTException: if a WLST error occurs
+    """
+    _method_name = 'undo'
+    _logger.entering(class_name=_class_name, method_name=_method_name)
+
+    try:
+        wlst.undo('true', 'y')
+    except wlst.WLSTException, e:
+        pwe = exception_helper.create_pywlst_exception('WLSDPLY-00069', _format_exception(e), error=e)
+        _logger.throwing(class_name=_class_name, method_name=_method_name, error=pwe)
+        raise pwe
+    _logger.exiting(class_name=_class_name, method_name=_method_name)
+
+
 def save():
     """
     Save the outstanding Weblogic Server configuration changes for the current edit session.
diff --git a/core/src/main/resources/oracle/weblogic/deploy/messages/wlsdeploy_rb.properties b/core/src/main/resources/oracle/weblogic/deploy/messages/wlsdeploy_rb.properties
index 016b5869f..c722260b2 100644
--- a/core/src/main/resources/oracle/weblogic/deploy/messages/wlsdeploy_rb.properties
+++ b/core/src/main/resources/oracle/weblogic/deploy/messages/wlsdeploy_rb.properties
@@ -73,6 +73,7 @@ WLSDPLY-00065=Failed to switch to the serverConfig MBean tree: {0}
 WLSDPLY-00066=Failed to switch to the domainRuntime MBean tree: {0}
 WLSDPLY-00067=Failed to switch to the custom MBean tree: {0}
 WLSDPLY-00068=Failed to change directories back to the original location {0}: {1}
+WLSDPLY-00069=wlst.undo() failed : {0}
 
 ###############################################################################
 #                      Util messages (1000 - 3999)                            #
@@ -1098,6 +1099,7 @@ WLSDPLY-19138=Failed to redeploy application {0}:{1}
 WLSDPLY-19139=Failed to start application {0}: {1}
 WLSDPLY-19140=Failed to stop application {0}: {1}
 WLSDPLY-19141=Failed to undeploy application {0}:{1}
+WLSDPLY-19142=Failed to undo changes: {0}
 
 # wlsdeploy/tool/util/attribute_setter.py
 WLSDPLY-19200=No target found with name {0}