diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2c69eb65276..4a559c73b8f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -85,7 +85,7 @@ jobs:
           ./scripts/ensure-version-bump-and-changelog.sh
         env:
           HEAD_SHA: ${{ github.event.pull_request.head.sha }}
-
+          PR_BASE: ${{ github.event.pull_request.base.ref }}
 
   wasm_tests:
     name: Run all WASM tests
diff --git a/scripts/ensure-version-bump-and-changelog.sh b/scripts/ensure-version-bump-and-changelog.sh
index 164af5126eb..1470ec3a5e4 100755
--- a/scripts/ensure-version-bump-and-changelog.sh
+++ b/scripts/ensure-version-bump-and-changelog.sh
@@ -5,9 +5,9 @@ set -ex;
 MANIFEST_PATH=$(cargo metadata --format-version=1 --no-deps | jq -e -r '.packages[] | select(.name == "'"$CRATE"'") | .manifest_path')
 DIR_TO_CRATE=$(dirname "$MANIFEST_PATH")
 
-MERGE_BASE=$(git merge-base "$HEAD_SHA" master) # Find the merge base. This ensures we only diff what was actually added in the PR.
+MERGE_BASE=$(git merge-base "$HEAD_SHA" "$PR_BASE") # Find the merge base. This ensures we only diff what was actually added in the PR.
 
-SRC_DIFF_TO_MASTER=$(git diff "$HEAD_SHA".."$MERGE_BASE" --name-status -- "$DIR_TO_CRATE/src" "$DIR_TO_CRATE/Cargo.toml")
+SRC_DIFF_TO_BASE=$(git diff "$HEAD_SHA".."$MERGE_BASE" --name-status -- "$DIR_TO_CRATE/src" "$DIR_TO_CRATE/Cargo.toml")
 CHANGELOG_DIFF=$(git diff "$HEAD_SHA".."$MERGE_BASE" --name-only -- "$DIR_TO_CRATE/CHANGELOG.md")
 
 VERSION_IN_CHANGELOG=$(awk -F' ' '/^## [0-9]+\.[0-9]+\.[0-9]+/{print $2; exit}' "$DIR_TO_CRATE/CHANGELOG.md")
@@ -20,7 +20,7 @@ if [[ "$VERSION_IN_CHANGELOG" != "$VERSION_IN_MANIFEST" ]]; then
 fi
 
 # If the source files of this crate weren't touched in this PR, exit early.
-if [ -z "$SRC_DIFF_TO_MASTER" ]; then
+if [ -z "$SRC_DIFF_TO_BASE" ]; then
   exit 0;
 fi