diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index aaf0c67..958dad1 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -13,9 +13,10 @@ jobs:
     runs-on: ubuntu-22.04
     container:
       image: heroku/heroku:${{ matrix.stack_number }}-build
+      options: --user root
     strategy:
       matrix:
-        stack_number: ["20", "22"]
+        stack_number: ["20", "22", "24"]
     env:
       STACK: heroku-${{ matrix.stack_number }}
     steps:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1cda33f..fa7e501 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 ## Unreleased
 
 - Warn when Aptfile contains no packages ([#126](https://github.com/heroku/heroku-buildpack-apt/pull/126))
+- Support sources parts directory for Heroku-24 compatibility ([#119](https://github.com/heroku/heroku-buildpack-apt/pull/119))
 
 ## 2024-03-14
 
diff --git a/Makefile b/Makefile
index cc13917..5dd5e97 100644
--- a/Makefile
+++ b/Makefile
@@ -1,8 +1,13 @@
-test: heroku-22-build heroku-20-build
+test: heroku-24-build heroku-22-build heroku-20-build
 
 shellcheck:
 	@shellcheck -x bin/compile bin/detect bin/release bin/report
 
+heroku-24-build:
+	@echo "Running tests in docker (heroku-24-build)..."
+	@docker run --user root -v $(shell pwd):/buildpack:ro --rm -it -e "STACK=heroku-24" heroku/heroku:24-build bash -c 'cp -r /buildpack /buildpack_test; cd /buildpack_test/; test/run;'
+	@echo ""
+
 heroku-22-build:
 	@echo "Running tests in docker (heroku-22-build)..."
 	@docker run -v $(shell pwd):/buildpack:ro --rm -it -e "STACK=heroku-22" heroku/heroku:22-build bash -c 'cp -r /buildpack /buildpack_test; cd /buildpack_test/; test/run;'
diff --git a/bin/compile b/bin/compile
index c10cdf1..711690a 100755
--- a/bin/compile
+++ b/bin/compile
@@ -53,6 +53,7 @@ echo "$STACK" > "$CACHE_DIR/.apt/STACK"
 APT_CACHE_DIR="$CACHE_DIR/apt/cache"
 APT_STATE_DIR="$CACHE_DIR/apt/state"
 APT_SOURCELIST_DIR="$CACHE_DIR/apt/sources"   # place custom sources.list here
+APT_SOURCEPARTS_DIR="$APT_SOURCELIST_DIR/sources.list.d"
 
 APT_SOURCES="$APT_SOURCELIST_DIR/sources.list"
 
@@ -75,6 +76,7 @@ else
   mkdir -p "$APT_SOURCELIST_DIR"   # make dir for sources
   cp -f "$BUILD_DIR/Aptfile" "$APT_CACHE_DIR/Aptfile"
   cat "/etc/apt/sources.list" > "$APT_SOURCES"    # no cp here
+  cp -R "/etc/apt/sources.list.d" "$APT_SOURCEPARTS_DIR"
   # add custom repositories from Aptfile to sources.list
   # like>>    :repo:deb http://cz.archive.ubuntu.com/ubuntu artful main universe
   if grep -q -e "^:repo:" "$BUILD_DIR/Aptfile"; then
@@ -85,7 +87,7 @@ fi
 
 APT_OPTIONS=("-o" "debug::nolocking=true" "-o" "dir::cache=$APT_CACHE_DIR" "-o" "dir::state=$APT_STATE_DIR")
 # Override the use of /etc/apt/sources.list (sourcelist) and /etc/apt/sources.list.d/* (sourceparts).
-APT_OPTIONS+=("-o" "dir::etc::sourcelist=$APT_SOURCES" "-o" "dir::etc::sourceparts=/dev/null")
+APT_OPTIONS+=("-o" "dir::etc::sourcelist=$APT_SOURCES" "-o" "dir::etc::sourceparts=$APT_SOURCEPARTS_DIR")
 
 topic "Updating apt caches"
 apt-get "${APT_OPTIONS[@]}" update 2>&1 | indent