diff --git a/apps/plugins/puzzles/genhelp.sh b/apps/plugins/puzzles/genhelp.sh
index 9aa304c0c1..3df7706b5d 100755
--- a/apps/plugins/puzzles/genhelp.sh
+++ b/apps/plugins/puzzles/genhelp.sh
@@ -1,10 +1,10 @@
 #!/bin/bash
 # usage: ./genhelp.sh
 #
-# expects halibut to be installed in $PATH:
-# http://www.chiark.greenend.org.uk/~sgtatham/halibut
+# Expects halibut to be installed in $PATH:
+# https://www.fwei.tk/git/halibut
 #
-# also requires host CC and lz4 library to be available
+# Also requires host CC and lz4 library to be available
 
 halibut --text src/puzzles.but
 
diff --git a/apps/plugins/puzzles/resync.sh b/apps/plugins/puzzles/resync.sh
new file mode 100755
index 0000000000..76679971a4
--- /dev/null
+++ b/apps/plugins/puzzles/resync.sh
@@ -0,0 +1,44 @@
+#!/bin/sh
+# Usage: resync.sh PUZZLES_PATH
+#
+# Automatic resync tool. Removes the current source snapshot in src/
+# and copies just the source files we need from the puzzles source
+# tree. Handles help generation as well. Stages changes in git.
+#
+# Expects a modified Halibut (https://www.fwei.tk/git/halibut) to be
+# installed in $PATH. Also requires host CC and lz4 library to be
+# available
+
+
+if [ $# -ne 1 ]
+then
+    echo -e "Usage: $0 PUZZLES_PATH\n"
+    echo "Automatically resync with upstream."
+    echo "PUZZLES_PATH is the path to a puzzles source tree."
+    exit
+fi
+
+echo "=== POTENTIALLY DANGEROUS OPERATION ==="
+echo "Are you sure you want to remove all files in src/?"
+echo -n "If so, type \"yes\" in all caps: "
+read ans
+if [ "YES" == $ans ]
+then
+    pushd "$(dirname "$0")" > /dev/null
+
+    echo "[1/5] Removing current src/ directory"
+    rm -rf src
+    echo "[2/5] Copying new sources"
+    mkdir src
+    cp -r "$1"/{*.c,*.h,*.R,*.but,LICENCE,README} src
+    echo "[3/5] Regenerating help"
+    ./genhelp.sh
+
+    echo "[4/5] Staging for commit"
+    git add src help
+    echo "[5/5] Successfully resynced with upstream"
+
+    popd > /dev/null
+else
+    echo "Did nothing."
+fi