diff --git a/.mailmap b/.mailmap
index 1065aa1f..0baed6f3 100644
--- a/.mailmap
+++ b/.mailmap
@@ -1 +1,4 @@
 <patrick@davids-neighbour.com> <83281+davidsneighbour@users.noreply.github.com>
+<runner@local> <runner@Mac-1716077439935.local>
+<runner@local> <runner@Mac-1716164017250.local>
+<runner@local> <runner@Mac-1716042973551.local>
diff --git a/scripts/mailmap b/scripts/mailmap
new file mode 100755
index 00000000..d611b6d0
--- /dev/null
+++ b/scripts/mailmap
@@ -0,0 +1,35 @@
+#!/bin/bash
+
+paster() {
+  # shellcheck disable=SC2162
+  while read email; do
+    [ -z "$email" ] || echo "$1" "$email"
+  done
+}
+
+grouper() {
+  IFS="<"
+  # shellcheck disable=SC2162
+  read x cur_name email
+  canonical_email="<"${email}
+  cur_emails=""
+
+  # shellcheck disable=SC2034,SC2162
+  while read x name email; do
+    if [ "$name" = "$cur_name" ]; then
+      cur_emails="$cur_emails <${email}"
+    else
+      echo "$cur_emails" | tr ' ' '\n' | paster "$canonical_email"
+      cur_name="$name"
+      canonical_email="<"${email}
+      cur_emails=""
+    fi
+  done
+  echo "$cur_emails" | tr ' ' '\n' | paster "$canonical_email"
+}
+
+root_dir="$(git rev-parse --show-cdup)"
+root_dir="${root_dir:-.}"
+cd "$root_dir" || exit
+git shortlog -s -e | tr '\t' '<' | sort -t '<' -k 2,2 -k 1,1nr | grouper | tee "${1:--a}" .mailmap
+git add .mailmap