diff --git a/juju_adaptor.go b/juju_adaptor.go
index 8bcfe2f..215b4b5 100644
--- a/juju_adaptor.go
+++ b/juju_adaptor.go
@@ -9,6 +9,9 @@ import (
 
 // Trace just calls AddStack.
 func Trace(err error) error {
+	if err == nil {
+		return nil
+	}
 	return AddStack(err)
 }