diff --git a/build b/build
index 890a9a1ff..e2c68bce1 100755
--- a/build
+++ b/build
@@ -188,8 +188,8 @@ make_zip() {
             esac
             ;;
     esac
-    ## one can only upgrade to 4.5.X from 4.4.8, when that's released.
-    ## Until that's released, there's no relup.
+    ## one can only upgrade to 4.5.X from 4.4.8 or later, when that's
+    ## released.  Until that's released, there's no relup.
     if [[ -z "$(ls -A _upgrade_base 2>/dev/null || true)" && "${PKG_VSN}" == 4.5.0* ]]; then
       has_relup='no'
     fi
diff --git a/include/emqx_release.hrl b/include/emqx_release.hrl
index 439a6ac14..eed5fc0b2 100644
--- a/include/emqx_release.hrl
+++ b/include/emqx_release.hrl
@@ -29,7 +29,7 @@
 
 -ifndef(EMQX_ENTERPRISE).
 
--define(EMQX_RELEASE, {opensource, "4.5.0"}).
+-define(EMQX_RELEASE, {opensource, "4.5.0-alpha.1"}).
 
 -else.
 
diff --git a/scripts/relup-base-packages.sh b/scripts/relup-base-packages.sh
index 5ac10ede2..f201a2dba 100755
--- a/scripts/relup-base-packages.sh
+++ b/scripts/relup-base-packages.sh
@@ -63,15 +63,21 @@ 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
+# 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
+otp_vsn_for() {
+  case "${1#[e|v]}" in
+    4.4.*)
+      echo "24.1.5-3"
+      ;;
+    4.5.*)
+      echo "$OTP_VSN"
+      ;;
+  esac
+}
 
 for tag in $(../scripts/relup-base-vsns.sh $EDITION | xargs echo -n); do
-    filename="$PROFILE-${tag#[e|v]}-otp$OTP_VSN-$SYSTEM-$ARCH.zip"
+    filename="$PROFILE-${tag#[e|v]}-otp$(otp_vsn_for "$tag")-$SYSTEM-$ARCH.zip"
     url="https://packages.emqx.io/$DIR/$tag/$filename"
     if [ ! -f "$filename" ] && curl -L -I -m 10 -o /dev/null -s -w "%{http_code}" "${url}" | grep -q -oE "^[23]+" ; then
         echo "downloading base package from ${url} ..."
diff --git a/scripts/relup-base-vsns.sh b/scripts/relup-base-vsns.sh
index 724f17d1a..d8e9bf380 100755
--- a/scripts/relup-base-vsns.sh
+++ b/scripts/relup-base-vsns.sh
@@ -89,12 +89,20 @@ for tag_to_del in "${TAGS_EXCLUDE[@]}"; do
     TAGS=( "${TAGS[@]/$tag_to_del}" )
 done
 
-# 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 that allows upgrading to 4.4.5.
+# 4.5.X versions uses the previous 4.4.Y as a base we emulate
+# that we are the last 4.4.Y version that allows upgrading to 4.5.X
 # We add that version, if available.
-if [[ "${CUR_SEMVER[0]}" = 4 && "${CUR_SEMVER[1]}" = 5 && "${CUR_SEMVER[2]}" = 0 ]]; then
-  [[ $(git tag -l "v4.4.8") ]] && TAGS+=( "v4.4.8" )
-  [[ $(git tag -l "e4.4.8") ]] && TAGS+=( "e4.4.8" )
+maybe_add_tag() {
+  local tag="$1"
+  if [[ $(git tag -l "$tag") ]]; then
+    TAGS+=( "$tag" )
+  fi
+}
+
+if [[ "${CUR_SEMVER[0]}" = 4 && "${CUR_SEMVER[1]}" = 5 ]]; then
+  for tag in "v4.4.8" "e4.4.8"; do
+    maybe_add_tag "$tag"
+  done
 fi
 
 for tag in "${TAGS[@]}"; do