1 files changed, 5 insertions, 2 deletions
diff --git a/synapse/logging/opentracing.py b/synapse/logging/opentracing.py
index 21dbd9f415..abe532d350 100644
--- a/synapse/logging/opentracing.py
+++ b/synapse/logging/opentracing.py
@@ -177,6 +177,7 @@ from canonicaljson import json
 from twisted.internet import defer
 
 from synapse.config import ConfigError
+from synapse.util import json_decoder
 
 if TYPE_CHECKING:
     from synapse.http.site import SynapseRequest
@@ -499,7 +500,9 @@ def start_active_span_from_edu(
     if opentracing is None:
         return _noop_context_manager()
 
-    carrier = json.loads(edu_content.get("context", "{}")).get("opentracing", {})
+    carrier = json_decoder.decode(edu_content.get("context", "{}")).get(
+        "opentracing", {}
+    )
     context = opentracing.tracer.extract(opentracing.Format.TEXT_MAP, carrier)
     _references = [
         opentracing.child_of(span_context_from_string(x))
@@ -699,7 +702,7 @@ def span_context_from_string(carrier):
     Returns:
         The active span context decoded from a string.
     """
-    carrier = json.loads(carrier)
+    carrier = json_decoder.decode(carrier)
     return opentracing.tracer.extract(opentracing.Format.TEXT_MAP, carrier)