diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 05ae117a..0dd3daa3 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -66,7 +66,7 @@ jobs:
             if [[ "${list}" == *","* ]]; then
               # If a comma is contained, consider it is a comma-separated list.
               # Drop leading and trailing whitespaces in each element.
-              sed -E 's/ *, */,/g; s/^.//' <<<",${list},"
+              sed -E 's/ *, */,/g; s/^.//; s/,,$/,/' <<<",${list},"
             else
               # Otherwise, consider it is a whitespace-separated list.
               # Convert whitespace characters into comma.
diff --git a/main.sh b/main.sh
index 44f45722..27f98b68 100755
--- a/main.sh
+++ b/main.sh
@@ -35,7 +35,7 @@ normalize_comma_or_space_separated() {
   if [[ "${list}" == *","* ]]; then
     # If a comma is contained, consider it is a comma-separated list.
     # Drop leading and trailing whitespaces in each element.
-    sed -E 's/ *, */,/g; s/^.//' <<<",${list},"
+    sed -E 's/ *, */,/g; s/^.//; s/,,$/,/' <<<",${list},"
   else
     # Otherwise, consider it is a whitespace-separated list.
     # Convert whitespace characters into comma.