diff --git a/gns3server/modules/dynamips/nodes/router.py b/gns3server/modules/dynamips/nodes/router.py
index 0b0d6492..c23f10f5 100644
--- a/gns3server/modules/dynamips/nodes/router.py
+++ b/gns3server/modules/dynamips/nodes/router.py
@@ -1498,7 +1498,7 @@ class Router(BaseVM):
         if self.startup_config or self.private_config:
             module_workdir = self.project.module_working_directory(self.manager.module_name.lower())
             startup_config_base64, private_config_base64 = yield from self.extract_config()
-            if startup_config_base64:
+            if self.startup_config and startup_config_base64:
                 try:
                     config = base64.b64decode(startup_config_base64).decode("utf-8", errors="replace")
                     config = "!\n" + config.replace("\r", "")
@@ -1509,7 +1509,7 @@ class Router(BaseVM):
                 except (binascii.Error, OSError) as e:
                     raise DynamipsError("Could not save the startup configuration {}: {}".format(config_path, e))
 
-            if private_config_base64:
+            if self.private_config and private_config_base64:
                 try:
                     config = base64.b64decode(private_config_base64).decode("utf-8", errors="replace")
                     config = "!\n" + config.replace("\r", "")