diff --git a/cirq-rigetti/requirements.txt b/cirq-rigetti/requirements.txt
index 2be61122ebb..4c504f4459c 100644
--- a/cirq-rigetti/requirements.txt
+++ b/cirq-rigetti/requirements.txt
@@ -9,6 +9,8 @@ pydantic~=1.8.2
 pyjwt~=1.7.1
 pyquil~=2.28.2; python_version < "3.7"
 pyquil~=3.0.0; python_version >= "3.7"
+# Remove once https://github.com/python-rapidjson/python-rapidjson/issues/166 is resolved.
+python-rapidjson<=1.6
 python-dateutil~=2.8.1
 qcs-api-client~=0.8.0
 retrying~=1.3.3