diff --git a/tools/update-tags-encoding b/tools/update-tags-encoding
new file mode 100755
index 0000000..87c5a5d
--- /dev/null
+++ b/tools/update-tags-encoding
@@ -0,0 +1,35 @@
+#!/bin/bash
+#
+# Check out the `entomologist-data` branch in a temporary worktree.
+# For each issue with a `tags` file:
+#     read
+
+set -e
+#set -x
+
+WORKTREE_DIR=$(mktemp --directory)
+git worktree add "${WORKTREE_DIR}" entomologist-data
+pushd "${WORKTREE_DIR}" > /dev/null
+
+for ISSUE_ID in $(find . -maxdepth 1 -type d -regextype posix-extended -regex '\./[0-9a-f]{32}'); do
+    if ! [[ -f "${ISSUE_ID}/tags" ]]; then
+        continue
+    fi
+
+    pushd "${ISSUE_ID}" > /dev/null
+
+    echo "${ISSUE_ID} has tags:"
+    TAGS=$(cat tags)
+    git rm tags
+    mkdir tags
+    for TAG in ${TAGS}; do
+        touch "tags/${TAG}"
+    done
+    git add tags
+    #git commit -m "issue ${ISSUE_ID}: update tags to new format"
+
+    popd > /dev/null
+done
+
+popd > /dev/null
+git worktree remove "${WORKTREE_DIR}"