diff --git a/gns3server/utils/asyncio.py b/gns3server/utils/asyncio.py
index 39e1ac8e..707c6901 100644
--- a/gns3server/utils/asyncio.py
+++ b/gns3server/utils/asyncio.py
@@ -52,7 +52,10 @@ def subprocess_check_output(*args, cwd=None, env=None):
     output = yield from proc.stdout.read()
     if output is None:
         return ""
-    return output.decode("utf-8")
+    # If we received garbage we ignore invalid characters
+    # it should happend only when user try to use another binary
+    # and the code of VPCS, dynamips... Will detect it's not the correct binary
+    return output.decode("utf-8", errors="ignore")
 
 
 @asyncio.coroutine