diff --git a/build b/build
index 024b9267d..056394bac 100755
--- a/build
+++ b/build
@@ -71,7 +71,14 @@ make_relup() {
     local lib_dir="_build/$PROFILE/rel/emqx/lib"
     local releases_dir="_build/$PROFILE/rel/emqx/releases"
     local name_pattern
-    name_pattern="${PROFILE}-$(./scripts/pkg-full-vsn.sh 'vsn_matcher')"
+    # 4.5.0 upgraded OTP from 24.1.5-3 to 24.3.4.2-1, so we need to
+    # fool the matcher to make it pick up the previous 4.4.X releases
+    # with older OTP.
+    if [[ "${PKG_VSN}" == 4.5.0* ]]; then
+      name_pattern="${PROFILE}-$(env OTP_VSN=24.1.5-3 ./scripts/pkg-full-vsn.sh 'vsn_matcher')"
+    else
+      name_pattern="${PROFILE}-$(./scripts/pkg-full-vsn.sh 'vsn_matcher')"
+    fi
     mkdir -p "$lib_dir" "$releases_dir" '_upgrade_base'
     local releases=()
     if [ -d "$releases_dir" ]; then
@@ -96,8 +103,8 @@ make_relup() {
     fi
     RELX_BASE_VERSIONS="$(IFS=, ; echo "${releases[*]}")"
     export RELX_BASE_VERSIONS
-    if [[ ${PKG_VSN} == 4.3* ]]; then
-        echo "EMQX 4.3 specific, overwrite OTP app versions"
+    if [[ ${PKG_VSN} == 4.3* || ${PKG_VSN} == 4.5.0* ]]; then
+        echo "EMQX 4.3/4.5 specific, overwrite OTP app versions"
         local emqx_rel_file="${releases_dir}/${PKG_VSN}/emqx.rel"
         if [ ! -f "${emqx_rel_file}" ]; then
             ./rebar3 as "${PROFILE}" release
@@ -115,7 +122,7 @@ make_relup() {
 
     # rollback rel file per releases
     #
-    if [[ ${PKG_VSN} == 4.3* ]]; then
+    if [[ ${PKG_VSN} == 4.3* || ${PKG_VSN} == 4.5.0* ]]; then
         echo "restore upgrade base rel files... "
         for rel in ${releases[*]};
         do
diff --git a/scripts/pkg-full-vsn.sh b/scripts/pkg-full-vsn.sh
index e118643c9..752bb62e2 100755
--- a/scripts/pkg-full-vsn.sh
+++ b/scripts/pkg-full-vsn.sh
@@ -18,7 +18,7 @@ case "${VSN_MATCH}" in
         PKG_VSN='*'
         ;;
     *)
-        echo "$0 ERROR: second arg must "
+        echo "$0 ERROR: arg must be either 'vsn_exact' or 'vsn_matcher'"
         exit 1
         ;;
 esac
diff --git a/scripts/relup-base-packages.sh b/scripts/relup-base-packages.sh
index 9505a68f0..5ac10ede2 100755
--- a/scripts/relup-base-packages.sh
+++ b/scripts/relup-base-packages.sh
@@ -63,6 +63,13 @@ cd -P -- "$(dirname -- "${BASH_SOURCE[0]}")/.."
 mkdir -p _upgrade_base
 pushd _upgrade_base
 
+# For 4.5, we upgrade from OTP 24.1.5-3 to 24.3.4.2-1, so we must manually
+# check the old OTP releases.
+CURRENT_VERSION="$(../pkg-vsn.sh)"
+if [[ "${CURRENT_VERSION}" = 4.5.0* ]]; then
+  OTP_VSN=24.1.5-3
+fi
+
 for tag in $(../scripts/relup-base-vsns.sh $EDITION | xargs echo -n); do
     filename="$PROFILE-${tag#[e|v]}-otp$OTP_VSN-$SYSTEM-$ARCH.zip"
     url="https://packages.emqx.io/$DIR/$tag/$filename"
diff --git a/scripts/relup-base-vsns.sh b/scripts/relup-base-vsns.sh
index 91c26823e..6b35fb196 100755
--- a/scripts/relup-base-vsns.sh
+++ b/scripts/relup-base-vsns.sh
@@ -61,6 +61,14 @@ esac
 # must not be empty for MacOS (bash 3.x)
 TAGS=( 'dummy' )
 TAGS_EXCLUDE=( 'dummy' )
+
+# first 4.5.0 version uses the previous 4.4.X as a base
+# we emulate that we are the last 4.4.X version.
+if [[ "${CUR_SEMVER[0]}" = 4 && "${CUR_SEMVER[1]}" = 5 && "${CUR_SEMVER[2]}" = 0 ]]; then
+  CUR_SEMVER[1]=4
+  CUR_SEMVER[2]=9999
+fi
+
 while read -r git_tag; do
     # shellcheck disable=SC2207
     semver=($(parse_semver "$git_tag"))