diff --git a/Dockerfile b/Dockerfile
index d94ea64..03a9609 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -17,13 +17,13 @@ RUN apt-get update && apt-get install -y sbt
 
 # install opensourcecobol4j
 RUN cd /root &&\
-    curl -L -o opensourcecobol4j-v1.0.19.tar.gz https://github.com/opensourcecobol/opensourcecobol4j/archive/refs/tags/v1.0.19.tar.gz &&\
-    tar zxvf opensourcecobol4j-v1.0.19.tar.gz &&\
-    cd opensourcecobol4j-1.0.19 &&\
+    curl -L -o opensourcecobol4j-v1.0.20.tar.gz https://github.com/opensourcecobol/opensourcecobol4j/archive/refs/tags/v1.0.20.tar.gz &&\
+    tar zxvf opensourcecobol4j-v1.0.20.tar.gz &&\
+    cd opensourcecobol4j-1.0.20 &&\
     ./configure --prefix=/usr/ &&\
     make &&\
     make install &&\
-    rm ../opensourcecobol4j-v1.0.19.tar.gz
+    rm ../opensourcecobol4j-v1.0.20.tar.gz
 
 # Install Open COBOL ESQL 4J
 RUN mkdir -p /usr/lib/Open-COBOL-ESQL-4j &&\
diff --git a/README.md b/README.md
index d0df90a..e7deeb0 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@
 Versions :
 
 - OS: Ubuntu
-- opensource COBOL 4J: v1.0.18
+- opensource COBOL 4J: v1.0.20
 - Open COBOL ESQL 4J: v1.0.3
 
 In order to "Hello World" program, run the following commands in the docker container
@@ -44,4 +44,4 @@ docker attach oc4j_client
 
 The container is for developers opensource COBOL 4J and Open COBOL ESQL 4J, not users of them.
 
-Copyright 2021-2023, Tokyo System House Co., Ltd. <opencobol@tsh-world.co.jp>
+Copyright 2021-2024, Tokyo System House Co., Ltd. <opencobol@tsh-world.co.jp>