diff --git a/external-libs/android32.Dockerfile b/external-libs/android32.Dockerfile
index 83d68a54..0746f9de 100644
--- a/external-libs/android32.Dockerfile
+++ b/external-libs/android32.Dockerfile
@@ -1,6 +1,6 @@
 FROM debian:stable
 
-RUN set -x && apt-get update && apt-get install -y unzip automake build-essential curl file pkg-config git python libtool libtinfo5
+RUN set -x && apt-get update && apt-get install -y unzip automake build-essential curl file pkg-config git python3 python-is-python3 libtool libtinfo5
 
 WORKDIR /opt/android
 ## INSTALL ANDROID SDK
@@ -80,8 +80,8 @@ RUN set -x \
     && ./b2 --build-type=minimal link=static runtime-link=static --with-chrono --with-date_time --with-filesystem --with-program_options --with-regex --with-serialization --with-system --with-thread --with-locale --build-dir=android --stagedir=android toolset=clang threading=multi threadapi=pthread target-os=android -sICONV_PATH=${PREFIX} install -j${NPROC}
 
 # download, configure and make Zlib
-ENV ZLIB_VERSION 1.2.13
-ENV ZLIB_HASH b3a24de97a8fdbc835b9833169501030b8977031bcb54b3b3ac13740f846ab30
+ENV ZLIB_VERSION 1.3
+ENV ZLIB_HASH ff0ba4c292013dbc27530b3a81e1f9a813cd39de01ca5e0f8bf355702efa593e
 RUN set -x \
     && curl -O https://zlib.net/zlib-${ZLIB_VERSION}.tar.gz \
     && echo "${ZLIB_HASH}  zlib-${ZLIB_VERSION}.tar.gz" | sha256sum -c \
diff --git a/external-libs/android32_x86.Dockerfile b/external-libs/android32_x86.Dockerfile
index f6207ec4..5271181a 100644
--- a/external-libs/android32_x86.Dockerfile
+++ b/external-libs/android32_x86.Dockerfile
@@ -1,6 +1,6 @@
 FROM debian:stable
 
-RUN set -x && apt-get update && apt-get install -y unzip automake build-essential curl file pkg-config git python libtool libtinfo5
+RUN set -x && apt-get update && apt-get install -y unzip automake build-essential curl file pkg-config git python3 python-is-python3 libtool libtinfo5
 
 WORKDIR /opt/android
 ## INSTALL ANDROID SDK
@@ -80,8 +80,8 @@ RUN set -x \
     && ./b2 --build-type=minimal link=static runtime-link=static --with-chrono --with-date_time --with-filesystem --with-program_options --with-regex --with-serialization --with-system --with-thread --with-locale --build-dir=android --stagedir=android toolset=clang threading=multi threadapi=pthread target-os=android -sICONV_PATH=${PREFIX} install -j${NPROC}
 
 # download, configure and make Zlib
-ENV ZLIB_VERSION 1.2.13
-ENV ZLIB_HASH b3a24de97a8fdbc835b9833169501030b8977031bcb54b3b3ac13740f846ab30
+ENV ZLIB_VERSION 1.3
+ENV ZLIB_HASH ff0ba4c292013dbc27530b3a81e1f9a813cd39de01ca5e0f8bf355702efa593e
 RUN set -x \
     && curl -O https://zlib.net/zlib-${ZLIB_VERSION}.tar.gz \
     && echo "${ZLIB_HASH}  zlib-${ZLIB_VERSION}.tar.gz" | sha256sum -c \
diff --git a/external-libs/android64.Dockerfile b/external-libs/android64.Dockerfile
index e48494cb..e7a6c731 100644
--- a/external-libs/android64.Dockerfile
+++ b/external-libs/android64.Dockerfile
@@ -1,6 +1,6 @@
 FROM debian:stable
 
-RUN set -x && apt-get update && apt-get install -y unzip automake build-essential curl file pkg-config git python libtool libtinfo5
+RUN set -x && apt-get update && apt-get install -y unzip automake build-essential curl file pkg-config git python3 python-is-python3 libtool libtinfo5
 
 WORKDIR /opt/android
 ## INSTALL ANDROID SDK
@@ -80,8 +80,8 @@ RUN set -x \
     && ./b2 --build-type=minimal link=static runtime-link=static --with-chrono --with-date_time --with-filesystem --with-program_options --with-regex --with-serialization --with-system --with-thread --with-locale --build-dir=android --stagedir=android toolset=clang threading=multi threadapi=pthread target-os=android -sICONV_PATH=${PREFIX} install -j${NPROC}
 
 # download, configure and make Zlib
-ENV ZLIB_VERSION 1.2.13
-ENV ZLIB_HASH b3a24de97a8fdbc835b9833169501030b8977031bcb54b3b3ac13740f846ab30
+ENV ZLIB_VERSION 1.3
+ENV ZLIB_HASH ff0ba4c292013dbc27530b3a81e1f9a813cd39de01ca5e0f8bf355702efa593e
 RUN set -x \
     && curl -O https://zlib.net/zlib-${ZLIB_VERSION}.tar.gz \
     && echo "${ZLIB_HASH}  zlib-${ZLIB_VERSION}.tar.gz" | sha256sum -c \
diff --git a/external-libs/android64_x86.Dockerfile b/external-libs/android64_x86.Dockerfile
index 60328b1a..500e09e0 100644
--- a/external-libs/android64_x86.Dockerfile
+++ b/external-libs/android64_x86.Dockerfile
@@ -1,6 +1,6 @@
 FROM debian:stable
 
-RUN set -x && apt-get update && apt-get install -y unzip automake build-essential curl file pkg-config git python libtool libtinfo5
+RUN set -x && apt-get update && apt-get install -y unzip automake build-essential curl file pkg-config git python3 python-is-python3 libtool libtinfo5
 
 WORKDIR /opt/android
 ## INSTALL ANDROID SDK
@@ -80,8 +80,8 @@ RUN set -x \
     && ./b2 --build-type=minimal link=static runtime-link=static --with-chrono --with-date_time --with-filesystem --with-program_options --with-regex --with-serialization --with-system --with-thread --with-locale --build-dir=android --stagedir=android toolset=clang threading=multi threadapi=pthread target-os=android -sICONV_PATH=${PREFIX} install -j${NPROC}
 
 # download, configure and make Zlib
-ENV ZLIB_VERSION 1.2.13
-ENV ZLIB_HASH b3a24de97a8fdbc835b9833169501030b8977031bcb54b3b3ac13740f846ab30
+ENV ZLIB_VERSION 1.3
+ENV ZLIB_HASH ff0ba4c292013dbc27530b3a81e1f9a813cd39de01ca5e0f8bf355702efa593e
 RUN set -x \
     && curl -O https://zlib.net/zlib-${ZLIB_VERSION}.tar.gz \
     && echo "${ZLIB_HASH}  zlib-${ZLIB_VERSION}.tar.gz" | sha256sum -c \