1 files changed, 1 insertions, 1 deletions
diff --git a/index.rst b/index.rst
index 41133c0..0bc8577 100644
--- a/index.rst
+++ b/index.rst
@@ -85,7 +85,7 @@ Specializing JSON object encoding::
     >>> def encode_complex(obj):
     ...     if isinstance(obj, complex):
     ...         return [obj.real, obj.imag]
-    ...     raise TypeError("%r is not JSON serializable" % (o,))
+    ...     raise TypeError(repr(o) + " is not JSON serializable")
     ...
     >>> json.dumps(2 + 1j, default=encode_complex)
     '[2.0, 1.0]'