diff --git a/gns3server/modules/dynamips/__init__.py b/gns3server/modules/dynamips/__init__.py
index 181347df..b36169e1 100644
--- a/gns3server/modules/dynamips/__init__.py
+++ b/gns3server/modules/dynamips/__init__.py
@@ -115,6 +115,7 @@ class Dynamips(BaseManager):
         self._devices = {}
         self._ghost_files = set()
         self._dynamips_path = None
+        self._project_lock = asyncio.Lock()
 
     @asyncio.coroutine
     def unload(self):
@@ -191,13 +192,14 @@ class Dynamips(BaseManager):
         :param project: Project instance
         """
 
-        for vm in self._vms.values():
-            if vm.project.id == project.id:
-                yield from vm.hypervisor.set_working_dir(project.module_working_directory(self.module_name.lower()))
+        with (yield from self._project_lock):
+            for vm in self._vms.values():
+                if vm.project.id == project.id:
+                    yield from vm.hypervisor.set_working_dir(project.module_working_directory(self.module_name.lower()))
 
-        for device in self._devices.values():
-            if device.project.id == project.id:
-                yield from device.hypervisor.set_working_dir(project.module_working_directory(self.module_name.lower()))
+            for device in self._devices.values():
+                if device.project.id == project.id:
+                    yield from device.hypervisor.set_working_dir(project.module_working_directory(self.module_name.lower()))
 
     @asyncio.coroutine
     def project_committed(self, project):
@@ -207,11 +209,11 @@ class Dynamips(BaseManager):
         :param project: Project instance
         """
 
-        pass
         # save the configs when the project is committed
-        #for vm in self._vms.values():
-        #    if vm.project.id == project.id:
-        #        yield from vm.save_configs()
+        with (yield from self._project_lock):
+            for vm in self._vms.values():
+                if vm.project.id == project.id:
+                    yield from vm.save_configs()
 
     @property
     def dynamips_path(self):