diff --git a/web/packages/core/src/internal/builder.ts b/web/packages/core/src/internal/builder.ts
index f60083800441..5e64f56ca5ed 100644
--- a/web/packages/core/src/internal/builder.ts
+++ b/web/packages/core/src/internal/builder.ts
@@ -1,4 +1,4 @@
-import type { RuffleInstanceBuilder } from "../../dist/ruffle_web";
+import type { RuffleInstanceBuilder } from "../../dist/ruffle_web-wasm_extensions";
 import { BaseLoadOptions, Duration, SecsDuration } from "../public/config";
 
 /**
diff --git a/web/packages/core/src/internal/player/inner.tsx b/web/packages/core/src/internal/player/inner.tsx
index d8af904f19b8..916414afd542 100644
--- a/web/packages/core/src/internal/player/inner.tsx
+++ b/web/packages/core/src/internal/player/inner.tsx
@@ -1,4 +1,4 @@
-import type { RuffleHandle, ZipWriter } from "../../../dist/ruffle_web";
+import type { RuffleHandle, ZipWriter } from "../../../dist/ruffle_web-wasm_extensions";
 import {
     AutoPlay,
     ContextMenu,
diff --git a/web/packages/core/src/load-ruffle.ts b/web/packages/core/src/load-ruffle.ts
index 6b474f61a9e4..fbcda77e0c21 100644
--- a/web/packages/core/src/load-ruffle.ts
+++ b/web/packages/core/src/load-ruffle.ts
@@ -9,7 +9,10 @@ import {
     signExtensions,
     referenceTypes,
 } from "wasm-feature-detect";
-import type { RuffleInstanceBuilder, ZipWriter } from "../dist/ruffle_web";
+import type {
+    RuffleInstanceBuilder,
+    ZipWriter,
+} from "../dist/ruffle_web-wasm_extensions";
 import { setPolyfillsOnLoad } from "./js-polyfills";
 
 import { internalSourceApi } from "./internal/internal-source-api";
@@ -45,7 +48,10 @@ async function fetchRuffle(
         ])
     ).every(Boolean);
 
-    if (!extensionsSupported) {
+    // @ts-expect-error TS2367 %FALLBACK_WASM% gets replaced in set_version.ts.
+    // %FALLBACK_WASM% is "ruffle_web" if this is a dual-wasm build.
+    // We don't say we're falling back if we have only an extension build.
+    if (!extensionsSupported && "%FALLBACK_WASM%" === "ruffle_web") {
         console.log(
             "Some WebAssembly extensions are NOT available, falling back to the vanilla WebAssembly module",
         );
@@ -63,11 +69,12 @@ async function fetchRuffle(
         ZipWriter,
     } = await (extensionsSupported
         ? import("../dist/ruffle_web-wasm_extensions")
-        : import("../dist/ruffle_web"));
+        : // @ts-expect-error TS2307 TypeScript compiler is trying to do the import.
+          import("../dist/%FALLBACK_WASM%"));
     let response;
     const wasmUrl = extensionsSupported
         ? new URL("../dist/ruffle_web-wasm_extensions_bg.wasm", import.meta.url)
-        : new URL("../dist/ruffle_web_bg.wasm", import.meta.url);
+        : new URL("../dist/%FALLBACK_WASM%_bg.wasm", import.meta.url);
     const wasmResponse = await fetch(wasmUrl);
     // The Pale Moon browser lacks full support for ReadableStream.
     // However, ReadableStream itself is defined.
diff --git a/web/packages/core/tools/build_wasm.ts b/web/packages/core/tools/build_wasm.ts
index bab1d3a41b28..1ef3a3966e04 100644
--- a/web/packages/core/tools/build_wasm.ts
+++ b/web/packages/core/tools/build_wasm.ts
@@ -140,13 +140,6 @@ function buildWasm(
         });
     }
 }
-function copyStandIn(from: string, to: string) {
-    const suffixes = [`_bg.wasm`, `_bg.wasm.d.ts`, `.js`, `.d.ts`];
-    console.log(`Copying ${from} as a stand-in for ${to}...`);
-    for (const suffix of suffixes) {
-        copyFileSync(`dist/${from}${suffix}`, `dist/${to}${suffix}`);
-    }
-}
 function detectWasmOpt() {
     try {
         execFileSync("wasm-opt", ["--version"]);
@@ -176,6 +169,4 @@ buildWasm(
 );
 if (buildWasmMvp) {
     buildWasm("web-vanilla-wasm", "ruffle_web", hasWasmOpt, false, wasmSource);
-} else {
-    copyStandIn("ruffle_web-wasm_extensions", "ruffle_web");
 }
diff --git a/web/packages/core/tools/set_version.ts b/web/packages/core/tools/set_version.ts
index a4fc8c1fc35d..5728a121e263 100644
--- a/web/packages/core/tools/set_version.ts
+++ b/web/packages/core/tools/set_version.ts
@@ -64,6 +64,11 @@ if (process.env["ENABLE_VERSION_SEAL"] === "true") {
     }
 }
 
+const fallbackWasmName =
+    process.env["BUILD_WASM_MVP"] === "true"
+        ? "ruffle_web"
+        : "ruffle_web-wasm_extensions";
+
 const options = {
     files: "dist/**",
     from: [
@@ -72,8 +77,16 @@ const options = {
         /%VERSION_CHANNEL%/g,
         /%BUILD_DATE%/g,
         /%COMMIT_HASH%/g,
+        /%FALLBACK_WASM%/g,
+    ],
+    to: [
+        versionNumber,
+        versionName,
+        versionChannel,
+        buildDate,
+        commitHash,
+        fallbackWasmName,
     ],
-    to: [versionNumber, versionName, versionChannel, buildDate, commitHash],
 };
 
 replaceInFileSync(options);