diff --git a/ortools/flatzinc/challenge/minizinc-challenge-ls.Dockerfile b/ortools/flatzinc/challenge/minizinc-challenge-ls.Dockerfile
index 86b9c8034c..d5d6d02634 100644
--- a/ortools/flatzinc/challenge/minizinc-challenge-ls.Dockerfile
+++ b/ortools/flatzinc/challenge/minizinc-challenge-ls.Dockerfile
@@ -1,6 +1,6 @@
 FROM minizinc/mznc2025:latest AS env
 
-ENV SRC_GIT_BRANCH v99bugfix
+ENV SRC_GIT_BRANCH=v99bugfix
 
 ENV TZ=America/Los_Angeles
 
@@ -31,4 +31,4 @@ RUN cp /root/or-tools/ortools/flatzinc/mznlib/*mzn /entry_data/mzn-lib
 # Patch the run scripts
 RUN  sed -i -e "s/-G/--fzn-flags --params=use_ls_only:true -p 1 -G/g" /minizinc/mzn-exec-fd
 RUN  sed -i -e "s/-G/--fzn-flags --params=use_ls_only:true,num_workers:3 -G/g" /minizinc/mzn-exec-free
-RUN  sed -i -e "s/-G/--fzn-flags --params=use_ls_only:true -G/g" /minizinc/mzn-exec-par
\ No newline at end of file
+RUN  sed -i -e "s/-G/--fzn-flags --params=use_ls_only:true -G/g" /minizinc/mzn-exec-par
diff --git a/ortools/flatzinc/challenge/minizinc-challenge.Dockerfile b/ortools/flatzinc/challenge/minizinc-challenge.Dockerfile
index 1113ff8778..0fdfc256e6 100644
--- a/ortools/flatzinc/challenge/minizinc-challenge.Dockerfile
+++ b/ortools/flatzinc/challenge/minizinc-challenge.Dockerfile
@@ -1,6 +1,6 @@
 FROM minizinc/mznc2025:latest AS env
 
-ENV SRC_GIT_BRANCH v99bugfix
+ENV SRC_GIT_BRANCH=v99bugfix
 
 ENV TZ=America/Los_Angeles
 
diff --git a/tools/docker/images/almalinux-9.Dockerfile b/tools/docker/images/almalinux-9.Dockerfile
index 4a6102159c..cf1d51d85f 100644
--- a/tools/docker/images/almalinux-9.Dockerfile
+++ b/tools/docker/images/almalinux-9.Dockerfile
@@ -62,12 +62,12 @@ COPY or-tools.snk /root/or-tools.snk
 ENV DOTNET_SNK=/root/or-tools.snk
 
 ARG SRC_GIT_BRANCH
-ENV SRC_GIT_BRANCH ${SRC_GIT_BRANCH:-main}
+ENV SRC_GIT_BRANCH=${SRC_GIT_BRANCH:-main}
 ARG SRC_GIT_SHA1
 ENV SRC_GIT_SHA1 ${SRC_GIT_SHA1:-unknown}
 
 ARG OR_TOOLS_PATCH
-ENV OR_TOOLS_PATCH ${OR_TOOLS_PATCH:-9999}
+ENV OR_TOOLS_PATCH=${OR_TOOLS_PATCH:-9999}
 
 # Download sources
 # use SRC_GIT_SHA1 to modify the command
diff --git a/tools/docker/images/alpine-edge.Dockerfile b/tools/docker/images/alpine-edge.Dockerfile
index 3e57be822e..9bb26f931b 100644
--- a/tools/docker/images/alpine-edge.Dockerfile
+++ b/tools/docker/images/alpine-edge.Dockerfile
@@ -40,12 +40,12 @@ COPY or-tools.snk /root/or-tools.snk
 ENV DOTNET_SNK=/root/or-tools.snk
 
 ARG SRC_GIT_BRANCH
-ENV SRC_GIT_BRANCH ${SRC_GIT_BRANCH:-main}
+ENV SRC_GIT_BRANCH=${SRC_GIT_BRANCH:-main}
 ARG SRC_GIT_SHA1
 ENV SRC_GIT_SHA1 ${SRC_GIT_SHA1:-unknown}
 
 ARG OR_TOOLS_PATCH
-ENV OR_TOOLS_PATCH ${OR_TOOLS_PATCH:-9999}
+ENV OR_TOOLS_PATCH=${OR_TOOLS_PATCH:-9999}
 
 # Download sources
 # use SRC_GIT_SHA1 to modify the command
diff --git a/tools/docker/images/archlinux.Dockerfile b/tools/docker/images/archlinux.Dockerfile
index 5ad355cfe5..92aec56c97 100644
--- a/tools/docker/images/archlinux.Dockerfile
+++ b/tools/docker/images/archlinux.Dockerfile
@@ -41,12 +41,12 @@ COPY or-tools.snk /root/or-tools.snk
 ENV DOTNET_SNK=/root/or-tools.snk
 
 ARG SRC_GIT_BRANCH
-ENV SRC_GIT_BRANCH ${SRC_GIT_BRANCH:-main}
+ENV SRC_GIT_BRANCH=${SRC_GIT_BRANCH:-main}
 ARG SRC_GIT_SHA1
 ENV SRC_GIT_SHA1 ${SRC_GIT_SHA1:-unknown}
 
 ARG OR_TOOLS_PATCH
-ENV OR_TOOLS_PATCH ${OR_TOOLS_PATCH:-9999}
+ENV OR_TOOLS_PATCH=${OR_TOOLS_PATCH:-9999}
 
 # Download sources
 # use SRC_GIT_SHA1 to modify the command
diff --git a/tools/docker/images/debian-11.Dockerfile b/tools/docker/images/debian-11.Dockerfile
index 2c514de3f8..1315560940 100644
--- a/tools/docker/images/debian-11.Dockerfile
+++ b/tools/docker/images/debian-11.Dockerfile
@@ -55,12 +55,12 @@ COPY or-tools.snk /root/or-tools.snk
 ENV DOTNET_SNK=/root/or-tools.snk
 
 ARG SRC_GIT_BRANCH
-ENV SRC_GIT_BRANCH ${SRC_GIT_BRANCH:-main}
+ENV SRC_GIT_BRANCH=${SRC_GIT_BRANCH:-main}
 ARG SRC_GIT_SHA1
 ENV SRC_GIT_SHA1 ${SRC_GIT_SHA1:-unknown}
 
 ARG OR_TOOLS_PATCH
-ENV OR_TOOLS_PATCH ${OR_TOOLS_PATCH:-9999}
+ENV OR_TOOLS_PATCH=${OR_TOOLS_PATCH:-9999}
 
 # Download sources
 # use SRC_GIT_SHA1 to modify the command
diff --git a/tools/docker/images/debian-12.Dockerfile b/tools/docker/images/debian-12.Dockerfile
index 424fd31282..da883df0ff 100644
--- a/tools/docker/images/debian-12.Dockerfile
+++ b/tools/docker/images/debian-12.Dockerfile
@@ -49,12 +49,12 @@ COPY or-tools.snk /root/or-tools.snk
 ENV DOTNET_SNK=/root/or-tools.snk
 
 ARG SRC_GIT_BRANCH
-ENV SRC_GIT_BRANCH ${SRC_GIT_BRANCH:-main}
+ENV SRC_GIT_BRANCH=${SRC_GIT_BRANCH:-main}
 ARG SRC_GIT_SHA1
 ENV SRC_GIT_SHA1 ${SRC_GIT_SHA1:-unknown}
 
 ARG OR_TOOLS_PATCH
-ENV OR_TOOLS_PATCH ${OR_TOOLS_PATCH:-9999}
+ENV OR_TOOLS_PATCH=${OR_TOOLS_PATCH:-9999}
 
 # Download sources
 # use SRC_GIT_SHA1 to modify the command
diff --git a/tools/docker/images/debian-13.Dockerfile b/tools/docker/images/debian-13.Dockerfile
index 5bb761afed..7c1e9fc1a9 100644
--- a/tools/docker/images/debian-13.Dockerfile
+++ b/tools/docker/images/debian-13.Dockerfile
@@ -50,12 +50,12 @@ COPY or-tools.snk /root/or-tools.snk
 ENV DOTNET_SNK=/root/or-tools.snk
 
 ARG SRC_GIT_BRANCH
-ENV SRC_GIT_BRANCH ${SRC_GIT_BRANCH:-main}
+ENV SRC_GIT_BRANCH=${SRC_GIT_BRANCH:-main}
 ARG SRC_GIT_SHA1
 ENV SRC_GIT_SHA1 ${SRC_GIT_SHA1:-unknown}
 
 ARG OR_TOOLS_PATCH
-ENV OR_TOOLS_PATCH ${OR_TOOLS_PATCH:-9999}
+ENV OR_TOOLS_PATCH=${OR_TOOLS_PATCH:-9999}
 
 # Download sources
 # use SRC_GIT_SHA1 to modify the command
diff --git a/tools/docker/images/debian-sid.Dockerfile b/tools/docker/images/debian-sid.Dockerfile
index 27fc2bb075..613a715a3e 100644
--- a/tools/docker/images/debian-sid.Dockerfile
+++ b/tools/docker/images/debian-sid.Dockerfile
@@ -52,12 +52,12 @@ COPY or-tools.snk /root/or-tools.snk
 ENV DOTNET_SNK=/root/or-tools.snk
 
 ARG SRC_GIT_BRANCH
-ENV SRC_GIT_BRANCH ${SRC_GIT_BRANCH:-main}
+ENV SRC_GIT_BRANCH=${SRC_GIT_BRANCH:-main}
 ARG SRC_GIT_SHA1
 ENV SRC_GIT_SHA1 ${SRC_GIT_SHA1:-unknown}
 
 ARG OR_TOOLS_PATCH
-ENV OR_TOOLS_PATCH ${OR_TOOLS_PATCH:-9999}
+ENV OR_TOOLS_PATCH=${OR_TOOLS_PATCH:-9999}
 
 # Download sources
 # use SRC_GIT_SHA1 to modify the command
diff --git a/tools/docker/images/fedora-40.Dockerfile b/tools/docker/images/fedora-40.Dockerfile
index 0fd6b0c905..7c487641d7 100644
--- a/tools/docker/images/fedora-40.Dockerfile
+++ b/tools/docker/images/fedora-40.Dockerfile
@@ -48,12 +48,12 @@ COPY or-tools.snk /root/or-tools.snk
 ENV DOTNET_SNK=/root/or-tools.snk
 
 ARG SRC_GIT_BRANCH
-ENV SRC_GIT_BRANCH ${SRC_GIT_BRANCH:-main}
+ENV SRC_GIT_BRANCH=${SRC_GIT_BRANCH:-main}
 ARG SRC_GIT_SHA1
 ENV SRC_GIT_SHA1 ${SRC_GIT_SHA1:-unknown}
 
 ARG OR_TOOLS_PATCH
-ENV OR_TOOLS_PATCH ${OR_TOOLS_PATCH:-9999}
+ENV OR_TOOLS_PATCH=${OR_TOOLS_PATCH:-9999}
 
 # Download sources
 # use SRC_GIT_SHA1 to modify the command
diff --git a/tools/docker/images/fedora-41.Dockerfile b/tools/docker/images/fedora-41.Dockerfile
index 9db9337a66..cc95fe4018 100644
--- a/tools/docker/images/fedora-41.Dockerfile
+++ b/tools/docker/images/fedora-41.Dockerfile
@@ -50,12 +50,12 @@ COPY or-tools.snk /root/or-tools.snk
 ENV DOTNET_SNK=/root/or-tools.snk
 
 ARG SRC_GIT_BRANCH
-ENV SRC_GIT_BRANCH ${SRC_GIT_BRANCH:-main}
+ENV SRC_GIT_BRANCH=${SRC_GIT_BRANCH:-main}
 ARG SRC_GIT_SHA1
 ENV SRC_GIT_SHA1 ${SRC_GIT_SHA1:-unknown}
 
 ARG OR_TOOLS_PATCH
-ENV OR_TOOLS_PATCH ${OR_TOOLS_PATCH:-9999}
+ENV OR_TOOLS_PATCH=${OR_TOOLS_PATCH:-9999}
 
 # Download sources
 # use SRC_GIT_SHA1 to modify the command
diff --git a/tools/docker/images/fedora-42.Dockerfile b/tools/docker/images/fedora-42.Dockerfile
index 485022bca2..be16996329 100644
--- a/tools/docker/images/fedora-42.Dockerfile
+++ b/tools/docker/images/fedora-42.Dockerfile
@@ -50,12 +50,12 @@ COPY or-tools.snk /root/or-tools.snk
 ENV DOTNET_SNK=/root/or-tools.snk
 
 ARG SRC_GIT_BRANCH
-ENV SRC_GIT_BRANCH ${SRC_GIT_BRANCH:-main}
+ENV SRC_GIT_BRANCH=${SRC_GIT_BRANCH:-main}
 ARG SRC_GIT_SHA1
 ENV SRC_GIT_SHA1 ${SRC_GIT_SHA1:-unknown}
 
 ARG OR_TOOLS_PATCH
-ENV OR_TOOLS_PATCH ${OR_TOOLS_PATCH:-9999}
+ENV OR_TOOLS_PATCH=${OR_TOOLS_PATCH:-9999}
 
 # Download sources
 # use SRC_GIT_SHA1 to modify the command
diff --git a/tools/docker/images/opensuse-leap.Dockerfile b/tools/docker/images/opensuse-leap.Dockerfile
index 300efe9555..52168a1c6a 100644
--- a/tools/docker/images/opensuse-leap.Dockerfile
+++ b/tools/docker/images/opensuse-leap.Dockerfile
@@ -48,12 +48,12 @@ COPY or-tools.snk /root/or-tools.snk
 ENV DOTNET_SNK=/root/or-tools.snk
 
 ARG SRC_GIT_BRANCH
-ENV SRC_GIT_BRANCH ${SRC_GIT_BRANCH:-main}
+ENV SRC_GIT_BRANCH=${SRC_GIT_BRANCH:-main}
 ARG SRC_GIT_SHA1
 ENV SRC_GIT_SHA1 ${SRC_GIT_SHA1:-unknown}
 
 ARG OR_TOOLS_PATCH
-ENV OR_TOOLS_PATCH ${OR_TOOLS_PATCH:-9999}
+ENV OR_TOOLS_PATCH=${OR_TOOLS_PATCH:-9999}
 
 # Download sources
 # use SRC_GIT_SHA1 to modify the command
diff --git a/tools/docker/images/rockylinux-9.Dockerfile b/tools/docker/images/rockylinux-9.Dockerfile
index c885bb3d87..86be1c55d5 100644
--- a/tools/docker/images/rockylinux-9.Dockerfile
+++ b/tools/docker/images/rockylinux-9.Dockerfile
@@ -62,12 +62,12 @@ COPY or-tools.snk /root/or-tools.snk
 ENV DOTNET_SNK=/root/or-tools.snk
 
 ARG SRC_GIT_BRANCH
-ENV SRC_GIT_BRANCH ${SRC_GIT_BRANCH:-main}
+ENV SRC_GIT_BRANCH=${SRC_GIT_BRANCH:-main}
 ARG SRC_GIT_SHA1
 ENV SRC_GIT_SHA1 ${SRC_GIT_SHA1:-unknown}
 
 ARG OR_TOOLS_PATCH
-ENV OR_TOOLS_PATCH ${OR_TOOLS_PATCH:-9999}
+ENV OR_TOOLS_PATCH=${OR_TOOLS_PATCH:-9999}
 
 # Download sources
 # use SRC_GIT_SHA1 to modify the command
diff --git a/tools/docker/images/ubuntu-20.04.Dockerfile b/tools/docker/images/ubuntu-20.04.Dockerfile
index 01564cf3ff..187e76077e 100644
--- a/tools/docker/images/ubuntu-20.04.Dockerfile
+++ b/tools/docker/images/ubuntu-20.04.Dockerfile
@@ -66,12 +66,12 @@ COPY or-tools.snk /root/or-tools.snk
 ENV DOTNET_SNK=/root/or-tools.snk
 
 ARG SRC_GIT_BRANCH
-ENV SRC_GIT_BRANCH ${SRC_GIT_BRANCH:-main}
+ENV SRC_GIT_BRANCH=${SRC_GIT_BRANCH:-main}
 ARG SRC_GIT_SHA1
 ENV SRC_GIT_SHA1 ${SRC_GIT_SHA1:-unknown}
 
 ARG OR_TOOLS_PATCH
-ENV OR_TOOLS_PATCH ${OR_TOOLS_PATCH:-9999}
+ENV OR_TOOLS_PATCH=${OR_TOOLS_PATCH:-9999}
 
 # Download sources
 # use SRC_GIT_SHA1 to modify the command
diff --git a/tools/docker/images/ubuntu-22.04.Dockerfile b/tools/docker/images/ubuntu-22.04.Dockerfile
index 1b32512b26..cd063522a4 100644
--- a/tools/docker/images/ubuntu-22.04.Dockerfile
+++ b/tools/docker/images/ubuntu-22.04.Dockerfile
@@ -64,12 +64,12 @@ COPY or-tools.snk /root/or-tools.snk
 ENV DOTNET_SNK=/root/or-tools.snk
 
 ARG SRC_GIT_BRANCH
-ENV SRC_GIT_BRANCH ${SRC_GIT_BRANCH:-main}
+ENV SRC_GIT_BRANCH=${SRC_GIT_BRANCH:-main}
 ARG SRC_GIT_SHA1
 ENV SRC_GIT_SHA1 ${SRC_GIT_SHA1:-unknown}
 
 ARG OR_TOOLS_PATCH
-ENV OR_TOOLS_PATCH ${OR_TOOLS_PATCH:-9999}
+ENV OR_TOOLS_PATCH=${OR_TOOLS_PATCH:-9999}
 
 # Download sources
 # use SRC_GIT_SHA1 to modify the command
diff --git a/tools/docker/images/ubuntu-24.04.Dockerfile b/tools/docker/images/ubuntu-24.04.Dockerfile
index 9cc69b1380..6cf39fa36e 100644
--- a/tools/docker/images/ubuntu-24.04.Dockerfile
+++ b/tools/docker/images/ubuntu-24.04.Dockerfile
@@ -58,12 +58,12 @@ COPY or-tools.snk /root/or-tools.snk
 ENV DOTNET_SNK=/root/or-tools.snk
 
 ARG SRC_GIT_BRANCH
-ENV SRC_GIT_BRANCH ${SRC_GIT_BRANCH:-main}
+ENV SRC_GIT_BRANCH=${SRC_GIT_BRANCH:-main}
 ARG SRC_GIT_SHA1
 ENV SRC_GIT_SHA1 ${SRC_GIT_SHA1:-unknown}
 
 ARG OR_TOOLS_PATCH
-ENV OR_TOOLS_PATCH ${OR_TOOLS_PATCH:-9999}
+ENV OR_TOOLS_PATCH=${OR_TOOLS_PATCH:-9999}
 
 # Download sources
 # use SRC_GIT_SHA1 to modify the command
diff --git a/tools/docker/images/ubuntu-24.10.Dockerfile b/tools/docker/images/ubuntu-24.10.Dockerfile
index 290a38decb..5e6b972a16 100644
--- a/tools/docker/images/ubuntu-24.10.Dockerfile
+++ b/tools/docker/images/ubuntu-24.10.Dockerfile
@@ -58,12 +58,12 @@ COPY or-tools.snk /root/or-tools.snk
 ENV DOTNET_SNK=/root/or-tools.snk
 
 ARG SRC_GIT_BRANCH
-ENV SRC_GIT_BRANCH ${SRC_GIT_BRANCH:-main}
+ENV SRC_GIT_BRANCH=${SRC_GIT_BRANCH:-main}
 ARG SRC_GIT_SHA1
 ENV SRC_GIT_SHA1 ${SRC_GIT_SHA1:-unknown}
 
 ARG OR_TOOLS_PATCH
-ENV OR_TOOLS_PATCH ${OR_TOOLS_PATCH:-9999}
+ENV OR_TOOLS_PATCH=${OR_TOOLS_PATCH:-9999}
 
 # Download sources
 # use SRC_GIT_SHA1 to modify the command
diff --git a/tools/docker/python/amd64/manylinux.Dockerfile b/tools/docker/python/amd64/manylinux.Dockerfile
index 1933738a40..415bcc52ce 100644
--- a/tools/docker/python/amd64/manylinux.Dockerfile
+++ b/tools/docker/python/amd64/manylinux.Dockerfile
@@ -22,12 +22,12 @@ RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
 ##  OR-TOOLS  ##
 ################
 FROM env AS devel
-ENV GIT_URL https://github.com/google/or-tools
+ENV GIT_URL=https://github.com/google/or-tools
 
 ARG GIT_BRANCH
-ENV GIT_BRANCH ${GIT_BRANCH:-main}
+ENV GIT_BRANCH=${GIT_BRANCH:-main}
 ARG GIT_SHA1
-ENV GIT_SHA1 ${GIT_SHA1:-unknown}
+ENV GIT_SHA1=${GIT_SHA1:-unknown}
 
 # Download sources
 # use GIT_SHA1 to modify the command
@@ -38,9 +38,9 @@ RUN git clone -b "${GIT_BRANCH}" --single-branch "$GIT_URL" /project \
 WORKDIR /project
 
 # Copy build script and setup env
-ENV PLATFORM x86_64
+ENV PLATFORM=x86_64
 ARG PYTHON_VERSION
-ENV PYTHON_VERSION ${PYTHON_VERSION:-3}
+ENV PYTHON_VERSION=${PYTHON_VERSION:-3}
 COPY build-manylinux.sh .
 RUN chmod a+x "build-manylinux.sh"
 
diff --git a/tools/docker/python/amd64/musllinux.Dockerfile b/tools/docker/python/amd64/musllinux.Dockerfile
index 4c2f64fdbf..4cc1706983 100644
--- a/tools/docker/python/amd64/musllinux.Dockerfile
+++ b/tools/docker/python/amd64/musllinux.Dockerfile
@@ -17,12 +17,12 @@ CMD ["/bin/sh"]
 ##  OR-TOOLS  ##
 ################
 FROM env AS devel
-ENV GIT_URL https://github.com/google/or-tools
+ENV GIT_URL=https://github.com/google/or-tools
 
 ARG GIT_BRANCH
-ENV GIT_BRANCH ${GIT_BRANCH:-main}
+ENV GIT_BRANCH=${GIT_BRANCH:-main}
 ARG GIT_SHA1
-ENV GIT_SHA1 ${GIT_SHA1:-unknown}
+ENV GIT_SHA1=${GIT_SHA1:-unknown}
 
 # Download sources
 # use GIT_SHA1 to modify the command
@@ -33,9 +33,9 @@ RUN git clone -b "${GIT_BRANCH}" --single-branch "$GIT_URL" /project \
 WORKDIR /project
 
 # Copy build script and setup env
-ENV PLATFORM x86_64
+ENV PLATFORM=x86_64
 ARG PYTHON_VERSION
-ENV PYTHON_VERSION ${PYTHON_VERSION:-3}
+ENV PYTHON_VERSION=${PYTHON_VERSION:-3}
 COPY build-musllinux.sh .
 RUN chmod a+x "build-musllinux.sh"
 
diff --git a/tools/docker/python/arm64/manylinux.Dockerfile b/tools/docker/python/arm64/manylinux.Dockerfile
index 116fe68de2..8edd33f373 100644
--- a/tools/docker/python/arm64/manylinux.Dockerfile
+++ b/tools/docker/python/arm64/manylinux.Dockerfile
@@ -24,12 +24,12 @@ RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
 ##  OR-TOOLS  ##
 ################
 FROM env AS devel
-ENV GIT_URL https://github.com/google/or-tools
+ENV GIT_URL=https://github.com/google/or-tools
 
 ARG GIT_BRANCH
-ENV GIT_BRANCH ${GIT_BRANCH:-main}
+ENV GIT_BRANCH=${GIT_BRANCH:-main}
 ARG GIT_SHA1
-ENV GIT_SHA1 ${GIT_SHA1:-unknown}
+ENV GIT_SHA1=${GIT_SHA1:-unknown}
 
 # Download sources
 # use GIT_SHA1 to modify the command
@@ -40,9 +40,9 @@ RUN git clone -b "${GIT_BRANCH}" --single-branch "$GIT_URL" /project \
 WORKDIR /project
 
 # Copy build script and setup env
-ENV PLATFORM aarch64
+ENV PLATFORM=aarch64
 ARG PYTHON_VERSION
-ENV PYTHON_VERSION ${PYTHON_VERSION:-3}
+ENV PYTHON_VERSION=${PYTHON_VERSION:-3}
 COPY build-manylinux.sh .
 RUN chmod a+x "build-manylinux.sh"
 
diff --git a/tools/docker/python/arm64/musllinux.Dockerfile b/tools/docker/python/arm64/musllinux.Dockerfile
index 719dc6417e..bbe93685f1 100644
--- a/tools/docker/python/arm64/musllinux.Dockerfile
+++ b/tools/docker/python/arm64/musllinux.Dockerfile
@@ -17,12 +17,12 @@ CMD ["/bin/sh"]
 ##  OR-TOOLS  ##
 ################
 FROM env AS devel
-ENV GIT_URL https://github.com/google/or-tools
+ENV GIT_URL=https://github.com/google/or-tools
 
 ARG GIT_BRANCH
-ENV GIT_BRANCH ${GIT_BRANCH:-main}
+ENV GIT_BRANCH=${GIT_BRANCH:-main}
 ARG GIT_SHA1
-ENV GIT_SHA1 ${GIT_SHA1:-unknown}
+ENV GIT_SHA1=${GIT_SHA1:-unknown}
 
 # Download sources
 # use GIT_SHA1 to modify the command
@@ -33,9 +33,9 @@ RUN git clone -b "${GIT_BRANCH}" --single-branch "${GIT_URL}" /project \
 WORKDIR /project
 
 # Copy build script and setup env
-ENV PLATFORM aarch64
+ENV PLATFORM=aarch64
 ARG PYTHON_VERSION
-ENV PYTHON_VERSION ${PYTHON_VERSION:-3}
+ENV PYTHON_VERSION=${PYTHON_VERSION:-3}
 COPY build-musllinux.sh .
 RUN chmod a+x "build-musllinux.sh"