diff --git a/app/modules/evaluation.py b/app/modules/evaluation.py
index fefd358..efdf5aa 100644
--- a/app/modules/evaluation.py
+++ b/app/modules/evaluation.py
@@ -234,6 +234,9 @@ class EvalModule(niobot.Module):
         """Run a command as another user."""
         if args is not None and args[0] == "%null%" or args is None:
             args = tuple()
+        
+        if args:
+            args = map(str, args)
         event = ctx.event
         event.sender = user
         event.body = ctx.invoking_prefix + command