diff --git a/.gitignore b/.gitignore
index 7be0d7764d..47582e6f98 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,6 +8,7 @@ public/trans
 public/compiled
 public/vendor/stockfish
 public/vendor/stockfish.wasm
+public/vendor/stockfish-mv.wasm
 target
 bin/.translate_version
 data/
diff --git a/ui/ceval/src/ctrl.ts b/ui/ceval/src/ctrl.ts
index 54eb227e5e..d019312cda 100644
--- a/ui/ceval/src/ctrl.ts
+++ b/ui/ceval/src/ctrl.ts
@@ -16,7 +16,7 @@ function sanIrreversible(variant: VariantKey, san: string): boolean {
 }
 
 function officialStockfish(variant: VariantKey): boolean {
-  return variant === 'standard' || variant === 'chess960' || variant === 'fromPosition';
+  return variant === 'standard' || variant === 'chess960';
 }
 
 export default function(opts: CevalOpts): CevalCtrl {
@@ -27,7 +27,7 @@ export default function(opts: CevalOpts): CevalCtrl {
 
   const pnaclSupported: boolean = !opts.failsafe && 'application/x-pnacl' in navigator.mimeTypes;
   const wasmSupported = typeof WebAssembly === 'object' && WebAssembly.validate(Uint8Array.of(0x0, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00));
-  const wasmThreadsSupported = officialStockfish(opts.variant.key) && wasmSupported && typeof SharedArrayBuffer === 'function' && new WebAssembly!.Memory({shared: true, initial: 8, maximum: 8}).buffer instanceof SharedArrayBuffer;
+  const wasmThreadsSupported = wasmSupported && typeof SharedArrayBuffer === 'function' && new WebAssembly!.Memory({shared: true, initial: 8, maximum: 8}).buffer instanceof SharedArrayBuffer;
   const minDepth = 6;
   const maxDepth = storedProp<number>(storageKey('ceval.max-depth'), 18);
   const multiPv = storedProp(storageKey('ceval.multipv'), opts.multiPvDefault || 1);
@@ -48,7 +48,7 @@ export default function(opts: CevalOpts): CevalCtrl {
     asmjs: li.assetUrl(sfPath + '.js', {sameDomain: true}),
     pnacl: pnaclSupported && li.assetUrl(sfPath + '.nmf'),
     wasm: wasmSupported && li.assetUrl(sfPath + '.wasm.js', {sameDomain: true}),
-    wasmThreaded: wasmThreadsSupported && 'vendor/stockfish.wasm/stockfish.js',
+    wasmThreaded: wasmThreadsSupported && (officialStockfish(opts.variant.key) ? 'vendor/stockfish.wasm/stockfish.js' : 'vendor/stockfish-mv.wasm/stockfish.js'),
     onCrash: opts.onCrash
   }, {
     minDepth,
diff --git a/ui/site/gulpfile.js b/ui/site/gulpfile.js
index 09010c9e49..582393bcb7 100644
--- a/ui/site/gulpfile.js
+++ b/ui/site/gulpfile.js
@@ -74,6 +74,15 @@ gulp.task('stockfish.wasm', function() {
   ]).pipe(gulp.dest('../../public/vendor/stockfish.wasm/'));
 });
 
+gulp.task('stockfish-mv.wasm', function() {
+  gulp.src([
+    require.resolve('stockfish-mv.wasm/stockfish.js'),
+    require.resolve('stockfish-mv.wasm/stockfish.js.mem'),
+    require.resolve('stockfish-mv.wasm/stockfish.wasm'),
+    require.resolve('stockfish-mv.wasm/pthread-main.js')
+  ]).pipe(gulp.dest('../../public/vendor/stockfish-mv.wasm/'));
+});
+
 gulp.task('prod-source', function() {
   return browserify('src/index.ts', {
     standalone: standalone
@@ -147,7 +156,7 @@ gulp.task('user-mod', function() {
     .pipe(gulp.dest(destination));
 });
 
-const tasks = ['git-sha', 'jquery-fill', 'ab', 'standalones', 'user-mod', 'stockfish.wasm'];
+const tasks = ['git-sha', 'jquery-fill', 'ab', 'standalones', 'user-mod', 'stockfish.wasm', 'stockfish-mv.wasm'];
 if (!process.env.TRAVIS || process.env.GITHUB_API_TOKEN) {
   if (!process.env.NO_SF) { // to skip SF download
     tasks.push('stockfish.pexe');
diff --git a/ui/site/package.json b/ui/site/package.json
index 28feac06f7..cdecd84504 100644
--- a/ui/site/package.json
+++ b/ui/site/package.json
@@ -22,6 +22,7 @@
     "vinyl-source-stream": "^1"
   },
   "dependencies": {
+    "stockfish-mv.wasm": "^0.2.0",
     "stockfish.wasm": "^0.2.0",
     "tablesort": "^5.0.0"
   }
diff --git a/yarn.lock b/yarn.lock
index 751a6cb67f..04bd9dc481 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -4425,6 +4425,11 @@ static-extend@^0.1.1:
     define-property "^0.2.5"
     object-copy "^0.1.0"
 
+stockfish-mv.wasm@^0.2.0:
+  version "0.2.0"
+  resolved "https://registry.yarnpkg.com/stockfish-mv.wasm/-/stockfish-mv.wasm-0.2.0.tgz#b402050ccca5455ed4419ffe2ad96d52a19c5f34"
+  integrity sha512-a2E/J0kBJIfoKdC8KPNy+xGQ4hvT/E10THMxjqmy1aHCgoV0pvOY+lgcLqvm6Q4c5IyFX5iDiY59ZrrtHedbEg==
+
 stockfish.wasm@^0.2.0:
   version "0.2.0"
   resolved "https://registry.yarnpkg.com/stockfish.wasm/-/stockfish.wasm-0.2.0.tgz#f92ee6a35c0ca3dacbd704adfec2df5101116503"