diff --git a/Interlace/lib/core/input.py b/Interlace/lib/core/input.py
index 4921ddd..935eb33 100644
--- a/Interlace/lib/core/input.py
+++ b/Interlace/lib/core/input.py
@@ -103,8 +103,9 @@ def process_commands(arguments):
         output = OutputHelper(arguments)
 
         # removing the trailing slash if any
-        if arguments.output[-1] == "/":
-            arguments.output = arguments.output[:-1]
+        if arguments.output:
+            if arguments.output[-1] == "/":
+                arguments.output = arguments.output[:-1]
 
         if arguments.port:
             if "," in arguments.port: