diff --git a/build-release b/build-release
index 6cf314f..fe9d7b3 100755
--- a/build-release
+++ b/build-release
@@ -480,6 +480,8 @@ build () {
 		cmake_opts="${cmake_opts} -DBUILD_GAME_NACL=ON -DBUILD_GAME_NACL_NEXE=ON -DBUILD_CGAME=ON -DBUILD_SGAME=ON -DBUILD_CLIENT=OFF -DBUILD_TTY_CLIENT=OFF -DBUILD_SERVER=OFF"
 	fi
 
+	local daemon_dir="${root_dir}/daemon"
+
 	if "${build_engine}"
 	then
 		engine_archive_basename="${target}"
@@ -498,7 +500,7 @@ build () {
 			fi
 
 			strip="${mingw_arch_prefix}-w64-mingw32-strip"
-			cmake_opts="${cmake_opts} -DCMAKE_TOOLCHAIN_FILE=${root_dir}/daemon/cmake/cross-toolchain-mingw${bitness}.cmake"
+			cmake_opts="${cmake_opts} -DCMAKE_TOOLCHAIN_FILE=${daemon_dir}/cmake/cross-toolchain-mingw${bitness}.cmake"
 			# unused
 			# cmake_opts="${cmake_opts} -DPKG_CONFIG_EXECUTABLE=${mingw_arch_prefix}-w64-mingw32-pkg-config"
 		fi
@@ -578,7 +580,7 @@ build () {
 			fi
 
 			strip="${mingw_arch_prefix}-w64-mingw32-strip"
-			cmake_opts="${cmake_opts} -DCMAKE_TOOLCHAIN_FILE=${root_dir}/daemon/cmake/cross-toolchain-mingw${bitness}.cmake"
+			cmake_opts="${cmake_opts} -DCMAKE_TOOLCHAIN_FILE=${daemon_dir}/cmake/cross-toolchain-mingw${bitness}.cmake"
 			# unused
 			# cmake_opts="${cmake_opts} -DPKG_CONFIG_EXECUTABLE=${mingw_arch_prefix}-w64-mingw32-pkg-config"
 		fi
@@ -599,7 +601,7 @@ build () {
 	then
 		# configuration
 
-		cmake -H"${root_dir}" \
+		cmake -H"${daemon_dir}" \
 			-B"${target_build_dir}" \
 			-G"Unix Makefiles" \
 			-D"CMAKE_C_FLAGS=${cmake_cflags}" \
@@ -609,11 +611,6 @@ build () {
 		|| throwError INTERNAL "${target} cmake failed"
 	fi
 
-	if "${build_vm}" || "${build_engine}"
-	then
-		daemon_dir="$(cmake -H"${root_dir}" -B"${target_build_dir}" -LH | grep '^DAEMON_DIR:' | sed -e 's/[^=]*=//')"
-	fi
-
 	if "${build_vm}"
 	then
 		# build vm
diff --git a/docker-build b/docker-build
index 6ad57ea..eccf4e4 100755
--- a/docker-build
+++ b/docker-build
@@ -115,8 +115,9 @@ def main():
     parser.add_argument("--clean", dest="clean", help="Delete previous target and universal zip builds.", action="store_true")
     parser.add_argument("--prune", dest="prune", help="Delete all docker images from previous target builds.", action="store_true")
     parser.add_argument("--reimage", dest="reimage", help="Rebuild the system docker images for the targets to build.", action="store_true")
-    parser.add_argument("--reference", dest="reference", metavar="REFERENCE", nargs='?', help="Git reference for targets to build.")
-    parser.add_argument("--targets", dest="targets", metavar="TARGETS", nargs='+', help="List of targets. Requires a reference. Available targets: {}".format(known_target_option_list))
+    parser.add_argument("--reference", dest="reference", metavar="REFERENCE", nargs='?', default="default", help="Git reference for targets to build.")
+    parser.add_argument("--engine-reference", dest="engine_reference", metavar="ENGINE_REFERENCE", nargs='?', default="default", help="Git reference for engine targets to build.")
+    parser.add_argument("--targets", dest="targets", metavar="TARGETS", nargs='+', help="List of targets. Available targets: {}".format(known_target_option_list))
     parser.add_argument("--unizip", dest="unizip", help="Make an universal zip out of built targets.", action="store_true")
     parser.add_argument("--chown", dest="chown", help="Change ownership of produced files, this option should never be needed as other tasks are expected to do it.", action="store_true")
     parser.add_argument("--docker", dest="docker", metavar="PATH", default="docker", help="Path to the docker binary. Default: %(default)s.")
@@ -125,9 +126,6 @@ def main():
 
     docker = Docker(args.docker)
 
-    if args.targets and not args.reference:
-        error("Building a target requires a reference.")
-
     target_list = []
 
     if args.targets:
@@ -150,7 +148,8 @@ def main():
     print("Clean: {}".format(str(args.clean)))
     print("Prune: {}".format(str(args.prune)))
     print("Reimage: {}".format(str(args.reimage)))
-    print("Reference: {}".format(str(args.reference)))
+    print("reference: {}".format(str(args.reference)))
+    print("Engine reference: {}".format(str(args.engine_reference)))
     print("Targets: {}".format(target_list_string))
     print("Unizip: {}".format(str(args.unizip)))
     print("Chown: {}".format(str(args.chown)))
@@ -174,6 +173,7 @@ def main():
 
     if target_list:
         reference_arg="--build-arg=reference={}".format(args.reference)
+        engine_reference_arg = "--build-arg=engine_reference={}".format(args.engine_reference)
 
         if args.reimage:
             docker.run("rmi", ["unvanquished-common-system"], stderr=subprocess.DEVNULL)
@@ -186,7 +186,7 @@ def main():
         docker.run("build", ["unvanquished-common-system", targets_arg])
 
         # Clone source repositories and build external dependencies.
-        docker.run("build", ["unvanquished-common-source", targets_arg, reference_arg])
+        docker.run("build", ["unvanquished-common-source", targets_arg, reference_arg, engine_reference_arg])
 
         # Build the targets.
         docker.run("mrun", ["--rm", targets_env,
@@ -243,7 +243,7 @@ def main():
             docker.run("commit", [container_id, "unvanquished-darling-darling"])
 
         # Clone source repositories.
-        docker.run("build", ["unvanquished-darling-source", reference_arg])
+        docker.run("build", ["unvanquished-darling-source", reference_arg, engine_reference_arg])
 
         # Build the targets.
         docker.run("mrun", ["--privileged", "--rm", targets_env,
diff --git a/docker/clone-repositories b/docker/clone-repositories
index 662d102..b6f5015 100755
--- a/docker/clone-repositories
+++ b/docker/clone-repositories
@@ -26,15 +26,22 @@
 
 source "$(dirname "${BASH_SOURCE[0]}")/common.sh"
 
-# Assume the desired revision of Unvanquished is near the tip
-# of some branch (last 20 commits)
-_exec git clone --depth 20 --no-single-branch \
-	'https://github.com/Unvanquished/Unvanquished.git' '/Unvanquished'
+_exec git clone 'https://github.com/Unvanquished/Unvanquished.git' '/Unvanquished'
 
 cd '/Unvanquished'
 
-_exec git checkout "${reference}"
+if [ "${reference:-default}" != 'default' ]
+then
+	_exec git checkout "${reference}"
+fi
 
-_exec git submodule update --init --depth 1 --recursive
+_exec git submodule update --init --recursive
+
+if [ "${engine_reference:-default}" != 'default' ]
+then
+	_exec git -C daemon checkout "${engine_reference}"
+
+	_exec git -C daemon submodule update --init --recursive
+fi
 
 _exec mkdir -p '/Unvanquished/build/release'
diff --git a/docker/unvanquished-common-source.Dockerfile b/docker/unvanquished-common-source.Dockerfile
index 2013a72..df22a0d 100644
--- a/docker/unvanquished-common-source.Dockerfile
+++ b/docker/unvanquished-common-source.Dockerfile
@@ -4,7 +4,8 @@ ARG targets
 RUN test -n "${targets}"
 
 ARG reference
-RUN test -n "${reference}"
+
+ARG engine_reference
 
 RUN /docker/clone-repositories
 
diff --git a/docker/unvanquished-darling-source.Dockerfile b/docker/unvanquished-darling-source.Dockerfile
index c3f561e..df4003c 100644
--- a/docker/unvanquished-darling-source.Dockerfile
+++ b/docker/unvanquished-darling-source.Dockerfile
@@ -1,6 +1,7 @@
 FROM unvanquished-darling-darling
 
 ARG reference
-RUN test -n "${reference}"
+
+ARG engine_reference
 
 RUN /docker/clone-repositories