diff --git a/Dockerfile b/Dockerfile
index 2a9db9d..2150baf 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -9,7 +9,7 @@ RUN apt-get update
 
 RUN apt-get -y install git python3.10 python3-pip librocksdb-dev libsnappy-dev libbz2-dev libz-dev liblz4-dev
 
-RUN pip3 install multidict aiohttp pylru python-rocksdb
+RUN pip3 install multidict aiohttp pylru python-rocksdb ujson
 
 RUN git clone -b $VERSION https://github.com/spesmilo/electrumx.git