diff --git a/.lgtm.yml b/.lgtm.yml
deleted file mode 100644
index 095578c..0000000
--- a/.lgtm.yml
+++ /dev/null
@@ -1,28 +0,0 @@
-path_classifiers:
-    test:
-        - src/test
-
-extraction:
-    cpp:
-        prepare:
-            packages:
-                - build-essential
-                - cmake
-                - libboost-all-dev
-                - libconfig++-dev
-        after_prepare:
-            - export WT_VERSION=4.5.0
-            - export WT_INSTALL_PREFIX=${LGTM_WORKSPACE}/wt-${WT_VERSION}
-            - pushd ${LGTM_WORKSPACE}
-            - git clone https://github.com/emweb/wt.git ${LGTM_WORKSPACE}/wt
-            - pushd ${LGTM_WORKSPACE}/wt
-            - git checkout ${WT_VERSION}
-            - cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=${WT_INSTALL_PREFIX} -DBUILD_EXAMPLES=OFF -DENABLE_LIBWTTEST=OFF -DCONNECTOR_FCGI=OFF
-            - make install
-            - popd
-        configure:
-            command:
-                - export WT_VERSION=4.5.0
-                - export WT_INSTALL_PREFIX=${LGTM_WORKSPACE}/wt-${WT_VERSION}
-                - cmake -DCMAKE_PREFIX_PATH=${WT_INSTALL_PREFIX} -DCMAKE_BUILD_TYPE=Release
-
diff --git a/Dockerfile-release b/Dockerfile-release
index 98d6037..2a6af19 100644
--- a/Dockerfile-release
+++ b/Dockerfile-release
@@ -32,7 +32,7 @@ RUN \
 RUN \
 	DIR=/tmp/wt && mkdir -p ${DIR} && cd ${DIR} && \
 	cmake . -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=${PREFIX} -DBUILD_EXAMPLES=OFF -DENABLE_LIBWTTEST=OFF -DCONNECTOR_FCGI=OFF -DINSTALL_THEMES=OFF && \
-	make && \
+	make -j$(nproc) && \
 	make install
 
 # Fileshelter
@@ -43,7 +43,7 @@ RUN \
 	PKG_CONFIG_PATH=/tmp/install/lib/pkgconfig CXXFLAGS="-I${PREFIX}/include" LDFLAGS="-L${PREFIX}/lib -Wl,--rpath-link=${PREFIX}/lib" cmake . -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=${PREFIX} -DCMAKE_PREFIX_PATH=${PREFIX} && \
 	LD_LIBRARY_PATH=${PREFIX}/lib VERBOSE=1 make && \
 	LD_LIBRARY_PATH=${PREFIX}/lib make test && \
-	make install && \
+	make install -j$(nproc) && \
 	mkdir -p ${PREFIX}/etc/ && \
 	cp conf/fileshelter.conf ${PREFIX}/etc
 
@@ -67,7 +67,7 @@ RUN \
 	rm -rf /tmp/fakeroot/share/Wt/resources/themes/default && \
 	rm -rf /tmp/fakeroot/share/Wt/resources/themes/polished && \
 	rm -rf /tmp/fakeroot/share/Wt/resources/themes/bootstrap/2 && \
-	rm -rf /tmp/fakeroot/share/Wt/resources/themes/bootstrap/5
+	rm -rf /tmp/fakeroot/share/Wt/resources/themes/bootstrap/3
 
 ## Release Stage
 FROM		alpine:3.17 AS release
diff --git a/INSTALL.md b/INSTALL.md
index 1bbc3fc..a47882a 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -1,6 +1,6 @@
 - [Installation](#installation)
   - [From Docker images](#from-docker-images)
-  - [From packages](#from-packages)
+  - [From Debian packages](#from-debian-packages)
   - [From source](#from-source)
 - [Deployment](#deployment)
   - [Configuration](#configuration)
@@ -11,28 +11,22 @@
 ## From Docker images
 Official _Docker_ images are available, please see detailed instructions at https://hub.docker.com/r/epoupon/fileshelter.
 
-## From packages
-### Debian Bullseye packages
-
-_Bullseye_ packages are provided for _amd64_ and _armhf_ architectures.
-
+## From Debian packages
+_Bookworm_ packages are provided for _amd64_ architectures.
 As root, trust the following debian package provider and add it in your list of repositories:
 ```sh
-wget -O - https://debian.poupon.dev/apt/debian/epoupon.gpg.key | apt-key add -
-echo "deb https://debian.poupon.dev/apt/debian buster main" > /etc/apt/sources.list.d/epoupon.list
+wget https://debian.poupon.dev/apt/debian/epoupon.gpg -P /usr/share/keyrings
+echo "deb [signed-by=/usr/share/keyrings/epoupon.gpg] https://debian.poupon.dev/apt/debian bookworm main" > /etc/apt/sources.list.d/epoupon.list
 ```
-
 To install or upgrade _fileshelter_:
 ```sh
 apt update
 apt install fileshelter
 ```
-
 The _fileshelter_ service is started just after the package installation, run by a dedicated _fileshelter_ system user.</br>
 Please refer to [Deployment](#deployment) for further configuration options.
-
 ## From source
-__Note__: this installation process and the default values of the configuration files have been written for _Debian Bullseye_. Therefore, you may have to adapt commands and/or paths in order to fit to your distribution.
+__Note__: this installation process and the default values of the configuration files have been written for _Debian Bookworm_. Therefore, you may have to adapt commands and/or paths in order to fit to your distribution.
 ### Debian/Ubuntu dependencies
 __Note__: a C++17 compiler is needed to compile _fileshelter_
 ```sh