diff --git a/circleci/images/Makefile b/circleci/images/Makefile
index 6b91a55..b35c2cd 100644
--- a/circleci/images/Makefile
+++ b/circleci/images/Makefile
@@ -2,6 +2,11 @@
 DOCKER_REPO ?= ghcr.io/citusdata
 SHA_SUFFIX := $(shell git rev-parse --short HEAD)
 
+# Upstream postgres git ref used to source-build PG19 (which is unreleased
+# and therefore not available via apt.postgresql.org). Override at build
+# time, e.g. `make PG19_SOURCE_REF=master push-extbuilder-19devel`.
+PG19_SOURCE_REF ?= 43649b6a53e9b3964e921cc962f5c977bce688fd
+
 # auto generated variables
 ifdef RELEASE
 	TAG_SUFFIX := -v${SHA_SUFFIX}
@@ -16,8 +21,11 @@ PG_UPGRADE_TESTER_VERSION=$(shell echo ${PG_VERSIONS}|tr ' ' '-'|sed 's/~//g')
 
 STYLE_CHECKER_TOOLS_VERSION=0.8.33
 
-# Upgrade tests for the PG major versions from PG_VERSIONS file
-CITUS_UPGRADE_PG_VERSIONS=$(shell head PG_VERSIONS|cut -c 6-|tr '\n' ' ')
+# Upgrade tests for the PG major versions from PG_VERSIONS file.
+# PG19 is excluded because no Citus release supports it yet; filter it
+# out by name so reordering PG_VERSIONS does not silently change which
+# major is dropped.
+CITUS_UPGRADE_PG_VERSIONS=$(shell grep -v '^PG19=' PG_VERSIONS|cut -c 6-|tr '\n' ' ')
 # 12.1.10 is the latest release of Citus 12 when the test is expanded to cover Citus 12
 CITUS_UPGRADE_VERSIONS_16=v12.1.12
 # Latest minor version of Citus 13
@@ -43,6 +51,7 @@ build-extbuilder-$1:
 		-f extbuilder/Dockerfile \
 		--build-arg=PG_VERSION=$1 \
 		--build-arg=PG_MAJOR=$2 \
+		--build-arg=PG19_SOURCE_REF=${PG19_SOURCE_REF} \
 		--tag=${DOCKER_REPO}/extbuilder:$3${TAG_SUFFIX}
 
 build-all:: build-extbuilder-$1
@@ -62,6 +71,7 @@ build-exttester-$1:
 		--build-arg=PG_VERSION=$1 \
 		--build-arg=PG_MAJOR=$2 \
 		--build-arg=PG_VERSION_CLEAN=$3 \
+		--build-arg=PG19_SOURCE_REF=${PG19_SOURCE_REF} \
 		--build-arg=CITUS_VERSION="$(call get_last_citus_version,$2)" \
 		--tag=${DOCKER_REPO}/exttester:$3${TAG_SUFFIX}
 
@@ -82,6 +92,7 @@ build-failtester-$1:
 		-f failtester/Dockerfile \
 		--build-arg=PG_VERSION=$1 \
 		--build-arg=PG_MAJOR=$2 \
+		--build-arg=PG19_SOURCE_REF=${PG19_SOURCE_REF} \
 		--tag=${DOCKER_REPO}/failtester:$3${TAG_SUFFIX}
 
 build-all:: build-failtester-$1
@@ -110,6 +121,7 @@ build-citusupgradetester-$1:
 		-f citusupgradetester/Dockerfile \
 		--build-arg=PG_VERSION=$1 \
 		--build-arg=PG_MAJOR=$2 \
+		--build-arg=PG19_SOURCE_REF=${PG19_SOURCE_REF} \
 		--build-arg=CITUS_VERSIONS="$(call get_citus_versions,$2)" \
 		--tag=${DOCKER_REPO}/citusupgradetester:$3${TAG_SUFFIX}
 
@@ -131,6 +143,7 @@ build-pgupgradetester:
 		pgupgradetester/ \
 		-f pgupgradetester/Dockerfile \
 		--build-arg=PG_VERSIONS="${PG_VERSIONS}" \
+		--build-arg=PG19_SOURCE_REF=${PG19_SOURCE_REF} \
 		--tag=${DOCKER_REPO}/pgupgradetester:${PG_UPGRADE_TESTER_VERSION}${TAG_SUFFIX}
 
 build-all:: build-pgupgradetester
diff --git a/circleci/images/PG_VERSIONS b/circleci/images/PG_VERSIONS
index 98c38dc..7054c61 100644
--- a/circleci/images/PG_VERSIONS
+++ b/circleci/images/PG_VERSIONS
@@ -1,3 +1,4 @@
-PG16=16.13
-PG17=17.9
-PG18=18.3
+PG16=16.14
+PG17=17.10
+PG18=18.4
+PG19=19devel
diff --git a/circleci/images/citusupgradetester/Dockerfile b/circleci/images/citusupgradetester/Dockerfile
index b434779..9cd7624 100644
--- a/circleci/images/citusupgradetester/Dockerfile
+++ b/circleci/images/citusupgradetester/Dockerfile
@@ -45,31 +45,85 @@ RUN locale-gen
 
 ARG PG_VERSION
 ARG PG_MAJOR
+ARG PG19_SOURCE_REF
 ENV PG_VERSION=$PG_VERSION
 ENV PG_MAJOR=$PG_MAJOR
+ENV PG19_SOURCE_REF=$PG19_SOURCE_REF
 
 
 RUN <<'EOF'
 # install postgres ecosystem for pg version: $PG_VERSION
 set -eux
 
-# install key and repositories
-curl -sf https://www.postgresql.org/media/keys/ACCC4CF8.asc | APT_KEY_DONT_WARN_ON_DANGEROUS_USAGE=1 apt-key add -
-echo "deb https://apt.postgresql.org/pub/repos/apt bookworm-pgdg main" >> /etc/apt/sources.list.d/postgresql.list
-echo "deb https://apt-archive.postgresql.org/pub/repos/apt bookworm-pgdg-archive main" >> /etc/apt/sources.list.d/postgresql.list
-
-apt-get update
-
-# infer the pgdgversion of postgres based on the $PG_VERSION
-pgdg_version=$(apt list -a postgresql-server-dev-${PG_MAJOR} 2>/dev/null | grep "${PG_VERSION}" | awk '{print $2}' | head -n1 )
-
-apt-get install -y --no-install-recommends --allow-downgrades \
-    libpq-dev=${pgdg_version} \
-    libpq5=${pgdg_version} \
-    postgresql-${PG_MAJOR}=${pgdg_version} \
-    postgresql-client-${PG_MAJOR}=${pgdg_version} \
-    postgresql-${PG_MAJOR}-dbgsym=${pgdg_version} \
-    postgresql-server-dev-${PG_MAJOR}=${pgdg_version} \
+if [ "${PG_MAJOR}" = "19" ]; then
+    # PG19 is unreleased and not on apt.postgresql.org. Build from a pinned
+    # upstream source ref so this image can still be produced. Note that no
+    # Citus release currently supports PG19, so the Makefile excludes PG19
+    # from CITUS_UPGRADE_PG_VERSIONS and this branch should not be hit by
+    # CI -- it exists so manual builds don't fail noisily.
+    apt-get update
+    apt-get install -y --no-install-recommends \
+        bison \
+        flex \
+        libxml2-dev \
+        pkg-config \
+        zlib1g-dev
+
+    src_dir=/tmp/pg19-src
+    rm -rf "${src_dir}"
+    mkdir -p "${src_dir}"
+    curl -fsL "https://codeload.github.com/postgres/postgres/tar.gz/${PG19_SOURCE_REF}" \
+        | tar -xzf - -C "${src_dir}" --strip-components=1
+    cd "${src_dir}"
+    ./configure \
+        --prefix=/usr/lib/postgresql/${PG_MAJOR} \
+        --datarootdir=/usr/share/postgresql/${PG_MAJOR} \
+        --includedir=/usr/include/postgresql/${PG_MAJOR} \
+        --sysconfdir=/etc/postgresql-common \
+        --with-openssl \
+        --with-icu \
+        --with-libxml \
+        --with-libxslt \
+        --with-lz4 \
+        --with-zstd \
+        --enable-rpath \
+        --with-system-tzdata=/usr/share/zoneinfo
+    make -sj"$(nproc)" world-bin
+    make install-world-bin
+    cd /
+    rm -rf "${src_dir}"
+
+    # apt-installed postgres packages normally create this user/group; do
+    # it manually for the source-build path so the chown in the next RUN
+    # step still works.
+    if ! getent group postgres >/dev/null; then
+        groupadd --system postgres
+    fi
+    if ! id postgres >/dev/null 2>&1; then
+        useradd --system --gid postgres --home-dir /var/lib/postgresql --shell /bin/bash postgres
+    fi
+    mkdir -p /var/lib/postgresql
+    chown -R postgres:postgres /var/lib/postgresql
+else
+    # install key and repositories
+    curl -sf https://www.postgresql.org/media/keys/ACCC4CF8.asc | APT_KEY_DONT_WARN_ON_DANGEROUS_USAGE=1 apt-key add -
+    echo "deb https://apt.postgresql.org/pub/repos/apt bookworm-pgdg main" >> /etc/apt/sources.list.d/postgresql.list
+    echo "deb https://apt-archive.postgresql.org/pub/repos/apt bookworm-pgdg-archive main" >> /etc/apt/sources.list.d/postgresql.list
+
+    apt-get update
+
+    # infer the pgdgversion of postgres based on the $PG_VERSION
+    pgdg_version=$(apt list -a postgresql-server-dev-${PG_MAJOR} 2>/dev/null | grep "${PG_VERSION}" | awk '{print $2}' | head -n1 )
+
+    apt-get install -y --no-install-recommends --allow-downgrades \
+        libpq-dev=${pgdg_version} \
+        libpq5=${pgdg_version} \
+        postgresql-${PG_MAJOR}=${pgdg_version} \
+        postgresql-client-${PG_MAJOR}=${pgdg_version} \
+        postgresql-${PG_MAJOR}-dbgsym=${pgdg_version} \
+        postgresql-server-dev-${PG_MAJOR}=${pgdg_version} \
+
+fi
 
 # clear apt cache
 rm -rf /var/lib/apt/lists/*
diff --git a/circleci/images/extbuilder/Dockerfile b/circleci/images/extbuilder/Dockerfile
index d703a28..f6c3a85 100644
--- a/circleci/images/extbuilder/Dockerfile
+++ b/circleci/images/extbuilder/Dockerfile
@@ -39,34 +39,76 @@ EOF
 
 ARG PG_VERSION
 ARG PG_MAJOR
+ARG PG19_SOURCE_REF
 ENV PG_VERSION=$PG_VERSION
 ENV PG_MAJOR=$PG_MAJOR
+ENV PG19_SOURCE_REF=$PG19_SOURCE_REF
 
 RUN <<'EOF'
 # install postgres ecosystem for pg version: $PG_VERSION
 set -eux
 
-# install key and repositories
-curl -sf https://www.postgresql.org/media/keys/ACCC4CF8.asc | APT_KEY_DONT_WARN_ON_DANGEROUS_USAGE=1 apt-key add -
-echo "deb https://apt.postgresql.org/pub/repos/apt bookworm-pgdg main" >> /etc/apt/sources.list.d/postgresql.list
-echo "deb https://apt-archive.postgresql.org/pub/repos/apt bookworm-pgdg-archive main" >> /etc/apt/sources.list.d/postgresql.list
+if [ "${PG_MAJOR}" = "19" ]; then
+    # PG19 is unreleased and not on apt.postgresql.org. Build from a pinned
+    # upstream source ref so this image can still be produced.
+    apt-get update
+    apt-get install -y --no-install-recommends \
+        bison \
+        flex \
+        libxml2-dev \
+        pkg-config \
+        zlib1g-dev
 
-apt-get update
+    src_dir=/tmp/pg19-src
+    rm -rf "${src_dir}"
+    mkdir -p "${src_dir}"
+    curl -fsL "https://codeload.github.com/postgres/postgres/tar.gz/${PG19_SOURCE_REF}" \
+        | tar -xzf - -C "${src_dir}" --strip-components=1
+    cd "${src_dir}"
+    ./configure \
+        --prefix=/usr/lib/postgresql/${PG_MAJOR} \
+        --datarootdir=/usr/share/postgresql/${PG_MAJOR} \
+        --includedir=/usr/include/postgresql/${PG_MAJOR} \
+        --sysconfdir=/etc/postgresql-common \
+        --with-openssl \
+        --with-icu \
+        --with-libxml \
+        --with-libxslt \
+        --with-lz4 \
+        --with-zstd \
+        --enable-rpath \
+        --with-system-tzdata=/usr/share/zoneinfo
+    make -sj"$(nproc)" world-bin
+    make install-world-bin
+    cd /
+    rm -rf "${src_dir}"
+else
+    # install key and repositories
+    curl -sf https://www.postgresql.org/media/keys/ACCC4CF8.asc | APT_KEY_DONT_WARN_ON_DANGEROUS_USAGE=1 apt-key add -
+    echo "deb https://apt.postgresql.org/pub/repos/apt bookworm-pgdg main" >> /etc/apt/sources.list.d/postgresql.list
+    echo "deb https://apt-archive.postgresql.org/pub/repos/apt bookworm-pgdg-archive main" >> /etc/apt/sources.list.d/postgresql.list
+
+    apt-get update
 
-# infer the pgdgversion of postgres based on the $PG_VERSION
-pgdg_version=$(apt list -a postgresql-server-dev-${PG_MAJOR} 2>/dev/null | grep "${PG_VERSION}" | awk '{print $2}' | head -n1 )
+    # infer the pgdgversion of postgres based on the $PG_VERSION
+    pgdg_version=$(apt list -a postgresql-server-dev-${PG_MAJOR} 2>/dev/null | grep "${PG_VERSION}" | awk '{print $2}' | head -n1 )
 
-apt-get install -y --no-install-recommends --allow-downgrades \
-    libpq-dev=${pgdg_version} \
-    libpq5=${pgdg_version} \
-    postgresql-${PG_MAJOR}=${pgdg_version} \
-    postgresql-client-${PG_MAJOR}=${pgdg_version} \
-    postgresql-${PG_MAJOR}-dbgsym=${pgdg_version} \
-    postgresql-server-dev-${PG_MAJOR}=${pgdg_version}
+    apt-get install -y --no-install-recommends --allow-downgrades \
+        libpq-dev=${pgdg_version} \
+        libpq5=${pgdg_version} \
+        postgresql-${PG_MAJOR}=${pgdg_version} \
+        postgresql-client-${PG_MAJOR}=${pgdg_version} \
+        postgresql-${PG_MAJOR}-dbgsym=${pgdg_version} \
+        postgresql-server-dev-${PG_MAJOR}=${pgdg_version}
+fi
 
 # clear apt cache
 rm -rf /var/lib/apt/lists/*
 EOF
 
+# make pg_config (installed by postgresql-server-dev-${PG_MAJOR} from apt or
+# by the PG19 source-build path) discoverable to extension builds
+ENV PATH=/usr/lib/postgresql/$PG_MAJOR/bin/:$PATH
+
 USER circleci
 WORKDIR /home/circleci
diff --git a/circleci/images/exttester/Dockerfile b/circleci/images/exttester/Dockerfile
index 4af0f75..843b64e 100644
--- a/circleci/images/exttester/Dockerfile
+++ b/circleci/images/exttester/Dockerfile
@@ -42,11 +42,21 @@ EOF
 ARG PG_VERSION
 ARG PG_VERSION_CLEAN
 ARG PG_MAJOR
+ARG PG19_SOURCE_REF
 
 WORKDIR /build/
-RUN curl -fLO "http://ftp.postgresql.org/pub/source/v${PG_VERSION_CLEAN}/postgresql-${PG_VERSION_CLEAN}.tar.bz2"
-
-RUN tar jxf "postgresql-${PG_VERSION_CLEAN}.tar.bz2"
+RUN <<'EOF'
+set -eux
+if [ "${PG_MAJOR}" = "19" ]; then
+    # PG19 is unreleased -- fetch the source from a pinned upstream git ref
+    mkdir -p "postgresql-${PG_VERSION_CLEAN}"
+    curl -fsL "https://codeload.github.com/postgres/postgres/tar.gz/${PG19_SOURCE_REF}" \
+        | tar -xzf - -C "postgresql-${PG_VERSION_CLEAN}" --strip-components=1
+else
+    curl -fLO "http://ftp.postgresql.org/pub/source/v${PG_VERSION_CLEAN}/postgresql-${PG_VERSION_CLEAN}.tar.bz2"
+    tar jxf "postgresql-${PG_VERSION_CLEAN}.tar.bz2"
+fi
+EOF
 
 # apply optional patches that might be required for a successful testsuite
 WORKDIR /build/postgresql-${PG_VERSION_CLEAN}/
@@ -142,36 +152,91 @@ RUN locale-gen
 
 ARG PG_VERSION
 ARG PG_MAJOR
+ARG PG19_SOURCE_REF
 ARG CITUS_VERSION
 ENV PG_VERSION=$PG_VERSION
 ENV PG_MAJOR=$PG_MAJOR
+ENV PG19_SOURCE_REF=$PG19_SOURCE_REF
 ENV CITUS_VERSION=$CITUS_VERSION
 
 RUN <<'EOF'
 # install postgres ecosystem for pg version: $PG_VERSION
 set -eux
 
-# install key and repositories
-curl -sf https://www.postgresql.org/media/keys/ACCC4CF8.asc | APT_KEY_DONT_WARN_ON_DANGEROUS_USAGE=1 apt-key add -
-echo "deb https://apt.postgresql.org/pub/repos/apt bookworm-pgdg main" >> /etc/apt/sources.list.d/postgresql.list
-echo "deb https://apt-archive.postgresql.org/pub/repos/apt bookworm-pgdg-archive main" >> /etc/apt/sources.list.d/postgresql.list
-
-apt-get update
-
-# infer the pgdgversion of postgres based on the $PG_VERSION
-pgdg_version=$(apt list -a postgresql-server-dev-${PG_MAJOR} 2>/dev/null | grep "${PG_VERSION}" | awk '{print $2}' | head -n1 )
-
-apt-get install -y --no-install-recommends --allow-downgrades \
-    libdbi-perl \
-    libpq-dev=${pgdg_version} \
-    libpq5=${pgdg_version} \
-    postgresql-${PG_MAJOR}=${pgdg_version} \
-    postgresql-client-${PG_MAJOR}=${pgdg_version} \
-    postgresql-${PG_MAJOR}-dbgsym=${pgdg_version} \
-    postgresql-server-dev-${PG_MAJOR}=${pgdg_version} \
-    postgresql-${PG_MAJOR}-wal2json
-
-apt-get install -y --no-install-recommends -t bookworm libdbd-pg-perl
+if [ "${PG_MAJOR}" = "19" ]; then
+    # PG19 is unreleased and not on apt.postgresql.org. Build from a pinned
+    # upstream source ref so this image can still be produced.
+    apt-get update
+    apt-get install -y --no-install-recommends \
+        bison \
+        flex \
+        libdbi-perl \
+        libxml2-dev \
+        pkg-config \
+        zlib1g-dev
+    apt-get install -y --no-install-recommends -t bookworm libdbd-pg-perl
+
+    src_dir=/tmp/pg19-src
+    rm -rf "${src_dir}"
+    mkdir -p "${src_dir}"
+    curl -fsL "https://codeload.github.com/postgres/postgres/tar.gz/${PG19_SOURCE_REF}" \
+        | tar -xzf - -C "${src_dir}" --strip-components=1
+    cd "${src_dir}"
+    ./configure \
+        --prefix=/usr/lib/postgresql/${PG_MAJOR} \
+        --datarootdir=/usr/share/postgresql/${PG_MAJOR} \
+        --includedir=/usr/include/postgresql/${PG_MAJOR} \
+        --sysconfdir=/etc/postgresql-common \
+        --with-openssl \
+        --with-icu \
+        --with-libxml \
+        --with-libxslt \
+        --with-lz4 \
+        --with-zstd \
+        --enable-rpath \
+        --with-system-tzdata=/usr/share/zoneinfo
+    make -sj"$(nproc)" world-bin
+    make install-world-bin
+    cd /
+    rm -rf "${src_dir}"
+
+    # apt-installed postgres packages normally create this user/group; do
+    # it manually for the source-build path so subsequent RUN steps that
+    # chown to postgres work.
+    if ! getent group postgres >/dev/null; then
+        groupadd --system postgres
+    fi
+    if ! id postgres >/dev/null 2>&1; then
+        useradd --system --gid postgres --home-dir /var/lib/postgresql --shell /bin/bash postgres
+    fi
+    mkdir -p /var/lib/postgresql
+    chown -R postgres:postgres /var/lib/postgresql
+
+    # wal2json is not yet packaged against PG19, so we skip it for this
+    # branch. Existing tests that depend on it should pin to PG <= 18.
+else
+    # install key and repositories
+    curl -sf https://www.postgresql.org/media/keys/ACCC4CF8.asc | APT_KEY_DONT_WARN_ON_DANGEROUS_USAGE=1 apt-key add -
+    echo "deb https://apt.postgresql.org/pub/repos/apt bookworm-pgdg main" >> /etc/apt/sources.list.d/postgresql.list
+    echo "deb https://apt-archive.postgresql.org/pub/repos/apt bookworm-pgdg-archive main" >> /etc/apt/sources.list.d/postgresql.list
+
+    apt-get update
+
+    # infer the pgdgversion of postgres based on the $PG_VERSION
+    pgdg_version=$(apt list -a postgresql-server-dev-${PG_MAJOR} 2>/dev/null | grep "${PG_VERSION}" | awk '{print $2}' | head -n1 )
+
+    apt-get install -y --no-install-recommends --allow-downgrades \
+        libdbi-perl \
+        libpq-dev=${pgdg_version} \
+        libpq5=${pgdg_version} \
+        postgresql-${PG_MAJOR}=${pgdg_version} \
+        postgresql-client-${PG_MAJOR}=${pgdg_version} \
+        postgresql-${PG_MAJOR}-dbgsym=${pgdg_version} \
+        postgresql-server-dev-${PG_MAJOR}=${pgdg_version} \
+        postgresql-${PG_MAJOR}-wal2json
+
+    apt-get install -y --no-install-recommends -t bookworm libdbd-pg-perl
+fi
 
 # clear apt cache
 rm -rf /var/lib/apt/lists/*
diff --git a/circleci/images/failtester/Dockerfile b/circleci/images/failtester/Dockerfile
index ac68c87..74b008a 100644
--- a/circleci/images/failtester/Dockerfile
+++ b/circleci/images/failtester/Dockerfile
@@ -46,29 +46,80 @@ RUN locale-gen
 
 ARG PG_VERSION
 ARG PG_MAJOR
+ARG PG19_SOURCE_REF
 ENV PG_VERSION=$PG_VERSION
 ENV PG_MAJOR=$PG_MAJOR
+ENV PG19_SOURCE_REF=$PG19_SOURCE_REF
 
 RUN <<'EOF'
 # install postgres ecosystem for pg version: $PG_VERSION
 
-# install key and repositories
-curl -sf https://www.postgresql.org/media/keys/ACCC4CF8.asc | APT_KEY_DONT_WARN_ON_DANGEROUS_USAGE=1 apt-key add -
-echo "deb https://apt.postgresql.org/pub/repos/apt bookworm-pgdg main" >> /etc/apt/sources.list.d/postgresql.list
-echo "deb https://apt-archive.postgresql.org/pub/repos/apt bookworm-pgdg-archive main" >> /etc/apt/sources.list.d/postgresql.list
+if [ "${PG_MAJOR}" = "19" ]; then
+    # PG19 is unreleased and not on apt.postgresql.org. Build from a pinned
+    # upstream source ref so this image can still be produced.
+    apt-get update
+    apt-get install -y --no-install-recommends \
+        bison \
+        flex \
+        libxml2-dev \
+        pkg-config \
+        zlib1g-dev
+
+    src_dir=/tmp/pg19-src
+    rm -rf "${src_dir}"
+    mkdir -p "${src_dir}"
+    curl -fsL "https://codeload.github.com/postgres/postgres/tar.gz/${PG19_SOURCE_REF}" \
+        | tar -xzf - -C "${src_dir}" --strip-components=1
+    cd "${src_dir}"
+    ./configure \
+        --prefix=/usr/lib/postgresql/${PG_MAJOR} \
+        --datarootdir=/usr/share/postgresql/${PG_MAJOR} \
+        --includedir=/usr/include/postgresql/${PG_MAJOR} \
+        --sysconfdir=/etc/postgresql-common \
+        --with-openssl \
+        --with-icu \
+        --with-libxml \
+        --with-libxslt \
+        --with-lz4 \
+        --with-zstd \
+        --enable-rpath \
+        --with-system-tzdata=/usr/share/zoneinfo
+    make -sj"$(nproc)" world-bin
+    make install-world-bin
+    cd /
+    rm -rf "${src_dir}"
+
+    # apt-installed postgres packages normally create this user/group; do
+    # it manually for the source-build path so the chown in the next RUN
+    # step still works.
+    if ! getent group postgres >/dev/null; then
+        groupadd --system postgres
+    fi
+    if ! id postgres >/dev/null 2>&1; then
+        useradd --system --gid postgres --home-dir /var/lib/postgresql --shell /bin/bash postgres
+    fi
+    mkdir -p /var/lib/postgresql
+    chown -R postgres:postgres /var/lib/postgresql
+else
+    # install key and repositories
+    curl -sf https://www.postgresql.org/media/keys/ACCC4CF8.asc | APT_KEY_DONT_WARN_ON_DANGEROUS_USAGE=1 apt-key add -
+    echo "deb https://apt.postgresql.org/pub/repos/apt bookworm-pgdg main" >> /etc/apt/sources.list.d/postgresql.list
+    echo "deb https://apt-archive.postgresql.org/pub/repos/apt bookworm-pgdg-archive main" >> /etc/apt/sources.list.d/postgresql.list
+
+    apt-get update
+
+    # infer the pgdgversion of postgres based on the $PG_VERSION
+    pgdg_version=$(apt list -a postgresql-server-dev-${PG_MAJOR} 2>/dev/null | grep "${PG_VERSION}" | awk '{print $2}' | head -n1 )
+
+    apt-get install -y --no-install-recommends --allow-downgrades \
+        libpq-dev=${pgdg_version} \
+        libpq5=${pgdg_version} \
+        postgresql-${PG_MAJOR}=${pgdg_version} \
+        postgresql-client-${PG_MAJOR}=${pgdg_version} \
+        postgresql-${PG_MAJOR}-dbgsym=${pgdg_version} \
+        postgresql-server-dev-${PG_MAJOR}=${pgdg_version} \
 
-apt-get update
-
-# infer the pgdgversion of postgres based on the $PG_VERSION
-pgdg_version=$(apt list -a postgresql-server-dev-${PG_MAJOR} 2>/dev/null | grep "${PG_VERSION}" | awk '{print $2}' | head -n1 )
-
-apt-get install -y --no-install-recommends --allow-downgrades \
-    libpq-dev=${pgdg_version} \
-    libpq5=${pgdg_version} \
-    postgresql-${PG_MAJOR}=${pgdg_version} \
-    postgresql-client-${PG_MAJOR}=${pgdg_version} \
-    postgresql-${PG_MAJOR}-dbgsym=${pgdg_version} \
-    postgresql-server-dev-${PG_MAJOR}=${pgdg_version} \
+fi
 
 # clear apt cache
 rm -rf /var/lib/apt/lists/*
diff --git a/circleci/images/pgupgradetester/Dockerfile b/circleci/images/pgupgradetester/Dockerfile
index 9e0237d..53414bc 100644
--- a/circleci/images/pgupgradetester/Dockerfile
+++ b/circleci/images/pgupgradetester/Dockerfile
@@ -40,7 +40,9 @@ rm -rf /var/lib/apt/lists/*
 EOF
 
 ARG PG_VERSIONS
+ARG PG19_SOURCE_REF
 ENV PG_VERSIONS=$PG_VERSIONS
+ENV PG19_SOURCE_REF=$PG19_SOURCE_REF
 
 # Hacky way to fetch all the pgdg versions so we can pin them
 # you will find the sequence '"'"' a couple of times. This is to
@@ -61,8 +63,15 @@ echo "deb https://apt-archive.postgresql.org/pub/repos/apt bookworm-pgdg-archive
 apt-get update
 
 pkgs=();
+source_build_majors=();
 for PG_VERSION in $PG_VERSIONS; do
     PG_MAJOR=$(echo ${PG_VERSION} | awk -F'[^0-9]*' '/[0-9]/ { print $1 }')
+    if [ "${PG_MAJOR}" = "19" ]; then
+        # PG19 is unreleased; fall through to a source build below instead
+        # of asking apt for it.
+        source_build_majors+=("${PG_MAJOR}");
+        continue;
+    fi
     pgdg_version=$(apt list -a postgresql-server-dev-${PG_MAJOR} 2>/dev/null | grep "${PG_VERSION}" | awk '{print $2}' | head -n1 )
     pkgs+=("postgresql-${PG_MAJOR}=${pgdg_version}")
     pkgs+=("postgresql-client-${PG_MAJOR}=${pgdg_version}")
@@ -71,14 +80,68 @@ for PG_VERSION in $PG_VERSIONS; do
     last_pgdg_version=$pgdg_version;
 done;
 
-pkgs+=("libpq-dev=${last_pgdg_version}");
-pkgs+=("libpq5=${last_pgdg_version}");
-
-echo ${pkgs[@]}
-
-apt-get install -y --no-install-recommends --allow-downgrades \
-  postgresql-common \
-  ${pkgs[@]} \
+if [ ${#pkgs[@]} -gt 0 ]; then
+    pkgs+=("libpq-dev=${last_pgdg_version}");
+    pkgs+=("libpq5=${last_pgdg_version}");
+
+    echo ${pkgs[@]}
+
+    apt-get install -y --no-install-recommends --allow-downgrades \
+      postgresql-common \
+      ${pkgs[@]} \
+
+fi
+
+# Source-build any majors that aren't on apt.postgresql.org (currently PG19).
+if [ ${#source_build_majors[@]} -gt 0 ]; then
+    apt-get install -y --no-install-recommends \
+        bison \
+        flex \
+        libicu-dev \
+        liblz4-dev \
+        libreadline-dev \
+        libssl-dev \
+        libxml2-dev \
+        libxslt-dev \
+        libzstd-dev \
+        pkg-config \
+        zlib1g-dev
+
+    if ! getent group postgres >/dev/null; then
+        groupadd --system postgres
+    fi
+    if ! id postgres >/dev/null 2>&1; then
+        useradd --system --gid postgres --home-dir /var/lib/postgresql --shell /bin/bash postgres
+    fi
+    mkdir -p /var/lib/postgresql
+    chown -R postgres:postgres /var/lib/postgresql
+
+    for PG_MAJOR in "${source_build_majors[@]}"; do
+        src_dir=/tmp/pg${PG_MAJOR}-src
+        rm -rf "${src_dir}"
+        mkdir -p "${src_dir}"
+        curl -fsL "https://codeload.github.com/postgres/postgres/tar.gz/${PG19_SOURCE_REF}" \
+            | tar -xzf - -C "${src_dir}" --strip-components=1
+        pushd "${src_dir}"
+        ./configure \
+            --prefix=/usr/lib/postgresql/${PG_MAJOR} \
+            --datarootdir=/usr/share/postgresql/${PG_MAJOR} \
+            --includedir=/usr/include/postgresql/${PG_MAJOR} \
+            --sysconfdir=/etc/postgresql-common \
+            --with-openssl \
+            --with-icu \
+            --with-libxml \
+            --with-libxslt \
+            --with-lz4 \
+            --with-zstd \
+            --enable-rpath \
+            --with-system-tzdata=/usr/share/zoneinfo
+        make -sj"$(nproc)" world-bin
+        make install-world-bin
+        popd
+        rm -rf "${src_dir}"
+    done
+fi
 
 # clear apt cache
 rm -rf /var/lib/apt/lists/*