diff --git a/prepare-release.sh b/prepare-release.sh
index c352f96..5a8a5d1 100755
--- a/prepare-release.sh
+++ b/prepare-release.sh
@@ -11,9 +11,9 @@ EXTENSION_FILE="extension.yaml"
 CHANGELOG_FILE="CHANGELOG.md"
 
 echo "Preparing extension for version $NEXT_RELEASE_VERSION"
-sed -i.bak "s/^version:.*/version: $NEXT_RELEASE_VERSION/" $EXTENSION_FILE
+sed -i "s/^version:.*/version: $NEXT_RELEASE_VERSION/" $EXTENSION_FILE
 echo "Updated version in $EXTENSION_FILE to $NEXT_RELEASE_VERSION"
 
 echo "Preparing changelog for version $NEXT_RELEASE_VERSION"
-sed -i.bak 's/^# /## Version /' $CHANGELOG_FILE
-echo "Updated headings in $CHANGELOG_FILE"
+sed -i "/^# $NEXT_RELEASE_VERSION/s/^# /## Version /" $CHANGELOG_FILE
+echo "Updated heading in $CHANGELOG_FILE"