diff --git a/.github/workflows/updater.sh b/.github/workflows/updater.sh
index a5b6d11..8e449f7 100644
--- a/.github/workflows/updater.sh
+++ b/.github/workflows/updater.sh
@@ -31,7 +31,7 @@ assets+=("https://github.com/$admin_repo/archive/refs/tags/${version}.zip")
 # THEME
 theme_repo="TryGhost/Casper"
 theme_version=$(curl --silent "https://api.github.com/repos/$theme_repo/releases" | jq -r '.[] | select( .prerelease != true ) | .tag_name' | sort -V | tail -1)
-assets+=("https://github.com/$theme_repo/archive/refs/tags/${version}.zip")
+assets+=("https://github.com/$theme_repo/archive/refs/tags/${theme_version}.zip")
 
 # Later down the script, we assume the version has only digits and dots
 # Sometimes the release name starts with a "v", so let's filter it out.
diff --git a/conf/casper.src b/conf/casper.src
index 2be34af..7ca2b10 100644
--- a/conf/casper.src
+++ b/conf/casper.src
@@ -1,5 +1,5 @@
-SOURCE_URL=https://github.com/TryGhost/Casper/archive/refs/tags/v5.2.4.zip
-SOURCE_SUM=d5558cd419c8d46bdc958064cb97f963d1ea793866414c025906ec15033512ed
+SOURCE_URL=https://github.com/TryGhost/Casper/archive/refs/tags/v5.1.5.zip
+SOURCE_SUM=ad883bf9e3ded051b21e4f2473cbcf32bdacdd8258f29bc45c4fdc0e3fc3e57f
 SOURCE_SUM_PRG=sha256sum
 SOURCE_FORMAT=zip
 SOURCE_IN_SUBDIR=true