diff --git a/Tuprules.lua b/Tuprules.lua
index a12634b0..e610484f 100644
--- a/Tuprules.lua
+++ b/Tuprules.lua
@@ -48,7 +48,7 @@ function compresspng(opts)
         cmds += rep{"advpng -q ${opts} ${output}", opts=advpng, output=output}
     end
     if deflopt then
-        cmds += rep{"node ${root}/tools/deflopt --wine ${output}",
+        cmds += rep{"node ${root}/tools/deflopt ${output}",
                     root=ROOTDIR,
                     output=output}
     end
diff --git a/tools/deflopt/deflopt.ts b/tools/deflopt/deflopt.ts
index 724ca92e..f9dde8d3 100644
--- a/tools/deflopt/deflopt.ts
+++ b/tools/deflopt/deflopt.ts
@@ -32,18 +32,18 @@ function parse(re : RegExp, output : string) {
 
 const DEFLOPT_EXE = `${root}/vendor/DeflOpt.exe`;
 
-export function deflopt({file, wine}: {file : string, wine: boolean}) {
+export function deflopt(file : string) {
     file = file.replace(/\//g, "\\");
 
     let cmd, args;
-    if (wine) {
+    if (process.platform === 'win32') {
+        cmd = DEFLOPT_EXE;
+        args = [file];
+    } else {
         cmd = "wine";
         // DeflOpt doesn't like absolute paths, it thinks they are Windows-style
         // command line switches.
         args = [DEFLOPT_EXE, file];
-    } else {
-        cmd = DEFLOPT_EXE;
-        args = [file];
     }
 
     const output = cp.execFileSync(cmd, args, {encoding: 'utf8'});
diff --git a/tools/deflopt/index.ts b/tools/deflopt/index.ts
index d37cb7e7..2b5c3f06 100644
--- a/tools/deflopt/index.ts
+++ b/tools/deflopt/index.ts
@@ -4,10 +4,9 @@ import program from 'commander';
 import {deflopt} from './deflopt.js';
 
 program
-    .option('--wine', 'Run executable with Wine')
     .arguments('<file>')
-    .action((file : string, {wine} : {wine?: boolean}) => {
-        const {processed, rewritten} = deflopt({file, wine: !!wine});
+    .action((file : string) => {
+        const {processed, rewritten} = deflopt(file);
         if (processed !== 1) {
             console.error(`Didn't process any files.`);
             process.exit(1);