diff --git a/images/baseos/Dockerfile b/images/baseos/Dockerfile
index faa61de065c..9171d593b11 100644
--- a/images/baseos/Dockerfile
+++ b/images/baseos/Dockerfile
@@ -19,7 +19,7 @@
 ARG GO_VER
 ARG UBUNTU_VER
 
-FROM ubuntu:${UBUNTU_VER} as base
+FROM ubuntu:${UBUNTU_VER:-22.04} AS base
 
 RUN apt update && apt install -y \
     tzdata
diff --git a/images/ccenv/Dockerfile b/images/ccenv/Dockerfile
index cfe625b4865..6798e56a368 100644
--- a/images/ccenv/Dockerfile
+++ b/images/ccenv/Dockerfile
@@ -17,7 +17,7 @@
 #
 
 ARG UBUNTU_VER
-FROM ubuntu:${UBUNTU_VER}
+FROM ubuntu:${UBUNTU_VER:-22.04}
 
 ARG TARGETARCH
 ARG TARGETOS
diff --git a/images/orderer/Dockerfile b/images/orderer/Dockerfile
index 0ed200428b6..ece115da660 100644
--- a/images/orderer/Dockerfile
+++ b/images/orderer/Dockerfile
@@ -21,7 +21,7 @@
 ###############################################################################
 
 ARG UBUNTU_VER
-FROM ubuntu:${UBUNTU_VER} as builder
+FROM ubuntu:${UBUNTU_VER:-22.04} AS builder
 
 ARG TARGETARCH
 ARG TARGETOS
@@ -48,7 +48,7 @@ RUN make orderer GO_TAGS=${GO_TAGS} FABRIC_VER=${FABRIC_VER}
 ###############################################################################
 
 ARG UBUNTU_VER
-FROM ubuntu:${UBUNTU_VER}
+FROM ubuntu:${UBUNTU_VER:-20.04}
 
 ARG FABRIC_VER
 
@@ -57,8 +57,8 @@ ARG FABRIC_VER
 # - docker run --rm debian:stretch grep '^hosts:' /etc/nsswitch.conf
 RUN echo 'hosts: files dns' > /etc/nsswitch.conf
 
-ENV     FABRIC_CFG_PATH /etc/hyperledger/fabric
-ENV     FABRIC_VER      ${FABRIC_VER}
+ENV FABRIC_CFG_PATH=/etc/hyperledger/fabric
+ENV FABRIC_VER=${FABRIC_VER}
 
 COPY    --from=builder  build/bin/orderer           /usr/local/bin
 COPY    --from=builder  sampleconfig/msp            ${FABRIC_CFG_PATH}/msp
diff --git a/images/peer/Dockerfile b/images/peer/Dockerfile
index a6a753869d4..761fa70287a 100644
--- a/images/peer/Dockerfile
+++ b/images/peer/Dockerfile
@@ -21,7 +21,7 @@
 ###############################################################################
 
 ARG UBUNTU_VER
-FROM ubuntu:${UBUNTU_VER} as builder
+FROM ubuntu:${UBUNTU_VER:-22.04} AS builder
 
 ARG TARGETARCH
 ARG TARGETOS
@@ -49,7 +49,7 @@ RUN make ccaasbuilder
 ###############################################################################
 
 ARG UBUNTU_VER
-FROM ubuntu:${UBUNTU_VER}
+FROM ubuntu:${UBUNTU_VER:-22.04}
 
 ARG TARGETOS
 ARG TARGETARCH
@@ -60,8 +60,8 @@ ARG FABRIC_VER
 # - docker run --rm debian:stretch grep '^hosts:' /etc/nsswitch.conf
 RUN echo 'hosts: files dns' > /etc/nsswitch.conf
 
-ENV     FABRIC_CFG_PATH /etc/hyperledger/fabric
-ENV     FABRIC_VER      ${FABRIC_VER}
+ENV FABRIC_CFG_PATH=/etc/hyperledger/fabric
+ENV FABRIC_VER=${FABRIC_VER}
 
 COPY    --from=builder  build/bin/peer          /usr/local/bin
 COPY    --from=builder  sampleconfig/msp        ${FABRIC_CFG_PATH}/msp