diff --git a/plugins/labels.py b/plugins/labels.py
index a040ef0a..7b98f3f6 100644
--- a/plugins/labels.py
+++ b/plugins/labels.py
@@ -185,12 +185,12 @@ class Plugin(BasePlugin):
                 try:
                     encoded_key = self.encode(key)
                 except:
-                    print_error('cannot encode', key)
+                    print_error('cannot encode', repr(key))
                     continue
                 try:
                     encoded_value = self.encode(value)
                 except:
-                    print_error('cannot encode', value)
+                    print_error('cannot encode', repr(value))
                     continue
                 bundle["labels"][encoded_key] = encoded_value