diff --git a/posix/payload b/posix/payload
index ae8be2e..1eb6e8a 100755
--- a/posix/payload
+++ b/posix/payload
@@ -1,6 +1,5 @@
 #!/bin/sh -e
 
-# TODO: verify checksum before extracting
 # TODO: extract self without resolving to $0 because it doesn't resolve links
 
 if [ -z "$XDG_CACHE_HOME" ]; then
@@ -14,10 +13,16 @@ if ! [ -d "$destdir" ]; then
 fi
 
 if ! [ "$(head -n 1 "$destdir"/ID/checksum 2>/dev/null)" = 'SUM' ]; then
+	rm -rf "$destdir"/ID
 	tail -c +BYTES "$0" | lz4 -dc | tar -x -C "$destdir"
 	echo "SUM" > "$destdir"/ID/checksum
 fi
 
+binname="$(basename "$0")"
+if echo "$binname" | grep -q \.tin$; then
+	binname="$(echo "$binname" | sed s/\.tin//)"
+fi
+
 ORIGIN="$destdir"/ID
 LD_LIBRARY_PATH="$ORIGIN/lib"
 PATH="$ORIGIN/bin":$PATH
@@ -27,5 +32,4 @@ export PATH
 
 # export LD_DEBUG='libs'
 
-# TODO: use $0 instead
-exec "$destdir"/ID/bin/"$(basename "$1")"
+exec "$destdir"/ID/bin/"$binname" "$@"