diff --git a/res/make-appdata.sh b/res/make-appdata.sh
index 90c3e193b..78d1865ee 100755
--- a/res/make-appdata.sh
+++ b/res/make-appdata.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 if [ $# -lt 2 ]; then
   echo "usage: $0 input output"
@@ -14,11 +14,15 @@ echo "  <releases>" >> "$2"
 for i in `git log --tags='v*' --no-walk --format="%as/%(describe:tags)"`; do
   releaseDate=${i%/*}
   releaseVer=${i#*/}
-  releaseType=stable
-  if [[ $releaseVer =~ "pre" ]]; then
-    releaseType=development
-  fi
-  echo "    <release version=\"${releaseVer/pre/~pre}\" date=\"$releaseDate\" type=\"$releaseType\">" >> "$2"
+  releaseVerProper=$releaseVer
+  case $releaseVer in
+    *pre*)
+      releaseType=development
+      releaseVerProper="${releaseVer%pre*}~pre${releaseVer#*pre}"
+      ;;
+    *) releaseType=stable;;
+  esac
+  echo "    <release version=\"${releaseVerProper}\" date=\"$releaseDate\" type=\"$releaseType\">" >> "$2"
   echo "      <url>https://github.com/tildearrow/furnace/releases/tag/$releaseVer</url>" >> "$2"
   echo "    </release>" >> "$2"
 done