1 files changed, 1 insertions, 1 deletions
diff --git a/synapse/util/__init__.py b/synapse/util/__init__.py
index 3ad4b28fc7..a13f11f8d8 100644
--- a/synapse/util/__init__.py
+++ b/synapse/util/__init__.py
@@ -28,7 +28,7 @@ logger = logging.getLogger(__name__)
 
 def _reject_invalid_json(val):
     """Do not allow Infinity, -Infinity, or NaN values in JSON."""
-    raise json.JSONDecodeError("Invalid JSON value: '%s'" % val)
+    raise ValueError("Invalid JSON value: '%s'" % val)
 
 
 # Create a custom encoder to reduce the whitespace produced by JSON encoding and