diff --git a/gns3server/modules/dynamips/nodes/router.py b/gns3server/modules/dynamips/nodes/router.py
index 9ebbbac8..2821169c 100644
--- a/gns3server/modules/dynamips/nodes/router.py
+++ b/gns3server/modules/dynamips/nodes/router.py
@@ -367,7 +367,7 @@ class Router(BaseVM):
             files += glob.glob(os.path.join(glob.escape(project_dir), "{}_i{}_flash[0-1]".format(self.platform, self.dynamips_id)))
             files += glob.glob(os.path.join(glob.escape(project_dir), "{}_i{}_rom".format(self.platform, self.dynamips_id)))
             files += glob.glob(os.path.join(glob.escape(project_dir), "{}_i{}_bootflash".format(self.platform, self.dynamips_id)))
-            files += glob.glob(os.path.join(glob.escape(project_dir), "{}_i{}_ssa").format(self.platform, self.dynamips_id))
+            files += glob.glob(os.path.join(glob.escape(project_dir), "{}_i{}_ssa".format(self.platform, self.dynamips_id)))
             for file in files:
                 try:
                     log.debug("Deleting file {}".format(file))