diff --git a/cli/tests/unit/flash_test.ts b/cli/tests/unit/flash_test.ts
index 375fdb8f366eb..e2e64dfe3ff49 100644
--- a/cli/tests/unit/flash_test.ts
+++ b/cli/tests/unit/flash_test.ts
@@ -2227,6 +2227,32 @@ Deno.test(
   },
 );
 
+Deno.test(
+  { permissions: { net: true } },
+  async function serveWithPromisePrototypeThenOverride() {
+    const originalThen = Promise.prototype.then;
+    try {
+      Promise.prototype.then = () => {
+        throw new Error();
+      };
+      const ac = new AbortController();
+      const listeningPromise = deferred();
+      const server = Deno.serve({
+        handler: (_req) => new Response("ok"),
+        hostname: "localhost",
+        port: 4501,
+        signal: ac.signal,
+        onListen: onListen(listeningPromise),
+        onError: createOnErrorCb(ac),
+      });
+      ac.abort();
+      await server;
+    } finally {
+      Promise.prototype.then = originalThen;
+    }
+  },
+);
+
 // https://github.com/denoland/deno/issues/15549
 Deno.test(
   { permissions: { net: true } },
diff --git a/cli/tests/unit/spawn_test.ts b/cli/tests/unit/spawn_test.ts
index 149886a1ceff7..10095be95ea00 100644
--- a/cli/tests/unit/spawn_test.ts
+++ b/cli/tests/unit/spawn_test.ts
@@ -812,3 +812,20 @@ Deno.test(
     assertStringIncludes(stdoutText, "typescript");
   },
 );
+
+Deno.test(
+  { permissions: { read: true, run: true } },
+  async function spawnWithPromisePrototypeThenOverride() {
+    const originalThen = Promise.prototype.then;
+    try {
+      Promise.prototype.then = () => {
+        throw new Error();
+      };
+      await Deno.spawn(Deno.execPath(), {
+        args: ["eval", "console.log('hello world')"],
+      });
+    } finally {
+      Promise.prototype.then = originalThen;
+    }
+  },
+);
diff --git a/core/00_primordials.js b/core/00_primordials.js
index 843eb8b294e13..d48dfde79e2c7 100644
--- a/core/00_primordials.js
+++ b/core/00_primordials.js
@@ -275,12 +275,15 @@
 
   const {
     ArrayPrototypeForEach,
+    ArrayPrototypeMap,
     FunctionPrototypeCall,
     Map,
     ObjectDefineProperty,
     ObjectFreeze,
+    ObjectPrototypeIsPrototypeOf,
     ObjectSetPrototypeOf,
     Promise,
+    PromisePrototype,
     PromisePrototypeThen,
     Set,
     SymbolIterator,
@@ -436,6 +439,29 @@
   primordials.PromisePrototypeCatch = (thisPromise, onRejected) =>
     PromisePrototypeThen(thisPromise, undefined, onRejected);
 
+  /**
+   * Creates a Promise that is resolved with an array of results when all of the
+   * provided Promises resolve, or rejected when any Promise is rejected.
+   * @param {unknown[]} values An array of Promises.
+   * @returns A new Promise.
+   */
+  primordials.SafePromiseAll = (values) =>
+    // Wrapping on a new Promise is necessary to not expose the SafePromise
+    // prototype to user-land.
+    new Promise((a, b) =>
+      SafePromise.all(
+        ArrayPrototypeMap(
+          values,
+          (p) => {
+            if (ObjectPrototypeIsPrototypeOf(PromisePrototype, p)) {
+              return new SafePromise((c, d) => PromisePrototypeThen(p, c, d));
+            }
+            return p;
+          },
+        ),
+      ).then(a, b)
+    );
+
   /**
    * Attaches a callback that is invoked when the Promise is settled (fulfilled or
    * rejected). The resolved value cannot be modified from the callback.
diff --git a/ext/fetch/26_fetch.js b/ext/fetch/26_fetch.js
index 5c824898de8cd..e522079bf75d2 100644
--- a/ext/fetch/26_fetch.js
+++ b/ext/fetch/26_fetch.js
@@ -529,14 +529,15 @@
         // 2.6.
         // Rather than consuming the body as an ArrayBuffer, this passes each
         // chunk to the feed as soon as it's available.
-        (async () => {
-          const reader = res.body.getReader();
-          while (true) {
-            const { value: chunk, done } = await reader.read();
-            if (done) break;
-            ops.op_wasm_streaming_feed(rid, chunk);
-          }
-        })().then(
+        PromisePrototypeThen(
+          (async () => {
+            const reader = res.body.getReader();
+            while (true) {
+              const { value: chunk, done } = await reader.read();
+              if (done) break;
+              ops.op_wasm_streaming_feed(rid, chunk);
+            }
+          })(),
           // 2.7
           () => core.close(rid),
           // 2.8
diff --git a/ext/flash/01_http.js b/ext/flash/01_http.js
index 5e6cb69aa357e..df013ce6578cc 100644
--- a/ext/flash/01_http.js
+++ b/ext/flash/01_http.js
@@ -29,11 +29,13 @@
   const {
     Function,
     ObjectPrototypeIsPrototypeOf,
-    PromiseAll,
+    Promise,
+    PromisePrototypeCatch,
+    PromisePrototypeThen,
+    SafePromiseAll,
     TypedArrayPrototypeSubarray,
     TypeError,
     Uint8Array,
-    Promise,
     Uint8ArrayPrototype,
   } = window.__bootstrap.primordials;
 
@@ -342,24 +344,27 @@
           }
           const reader = respBody.getReader(); // Aquire JS lock.
           try {
-            core.opAsync(
-              "op_flash_write_resource",
-              http1Response(
-                method,
-                innerResp.status ?? 200,
-                innerResp.headerList,
-                0, // Content-Length will be set by the op.
-                null,
-                true,
+            PromisePrototypeThen(
+              core.opAsync(
+                "op_flash_write_resource",
+                http1Response(
+                  method,
+                  innerResp.status ?? 200,
+                  innerResp.headerList,
+                  0, // Content-Length will be set by the op.
+                  null,
+                  true,
+                ),
+                serverId,
+                i,
+                resourceBacking.rid,
+                resourceBacking.autoClose,
               ),
-              serverId,
-              i,
-              resourceBacking.rid,
-              resourceBacking.autoClose,
-            ).then(() => {
-              // Release JS lock.
-              readableStreamClose(respBody);
-            });
+              () => {
+                // Release JS lock.
+                readableStreamClose(respBody);
+              },
+            );
           } catch (error) {
             await reader.cancel(error);
             throw error;
@@ -486,10 +491,16 @@
     const serverId = core.ops.op_flash_serve(listenOpts);
     const serverPromise = core.opAsync("op_flash_drive_server", serverId);
 
-    core.opAsync("op_flash_wait_for_listening", serverId).then((port) => {
-      onListen({ hostname: listenOpts.hostname, port });
-    }).catch(() => {});
-    const finishedPromise = serverPromise.catch(() => {});
+    PromisePrototypeCatch(
+      PromisePrototypeThen(
+        core.opAsync("op_flash_wait_for_listening", serverId),
+        (port) => {
+          onListen({ hostname: listenOpts.hostname, port });
+        },
+      ),
+      () => {},
+    );
+    const finishedPromise = PromisePrototypeCatch(serverPromise, () => {});
 
     const server = {
       id: serverId,
@@ -554,7 +565,27 @@
             let resp;
             try {
               resp = handler(req);
-              if (resp instanceof Promise || typeof resp?.then === "function") {
+              if (resp instanceof Promise) {
+                PromisePrototypeCatch(
+                  PromisePrototypeThen(
+                    resp,
+                    (resp) =>
+                      handleResponse(
+                        req,
+                        resp,
+                        body,
+                        hasBody,
+                        method,
+                        serverId,
+                        i,
+                        respondFast,
+                        respondChunked,
+                      ),
+                  ),
+                  onError,
+                );
+                continue;
+              } else if (typeof resp?.then === "function") {
                 resp.then((resp) =>
                   handleResponse(
                     req,
@@ -595,7 +626,7 @@
 
     signal?.addEventListener("abort", () => {
       clearInterval(dateInterval);
-      server.close().then(() => {}, () => {});
+      PromisePrototypeThen(server.close(), () => {}, () => {});
     }, {
       once: true,
     });
@@ -638,8 +669,8 @@
       }, 1000);
     }
 
-    await PromiseAll([
-      server.serve().catch(console.error),
+    await SafePromiseAll([
+      PromisePrototypeCatch(server.serve(), console.error),
       serverPromise,
     ]);
   }
diff --git a/ext/web/06_streams.js b/ext/web/06_streams.js
index 6dbf69951e2ad..752ef3ad6ce73 100644
--- a/ext/web/06_streams.js
+++ b/ext/web/06_streams.js
@@ -35,7 +35,6 @@
     ObjectPrototypeIsPrototypeOf,
     ObjectSetPrototypeOf,
     Promise,
-    PromiseAll,
     PromisePrototypeCatch,
     PromisePrototypeThen,
     PromiseReject,
@@ -43,6 +42,7 @@
     queueMicrotask,
     RangeError,
     ReflectHas,
+    SafePromiseAll,
     SharedArrayBuffer,
     Symbol,
     SymbolAsyncIterator,
@@ -2317,7 +2317,8 @@
           });
         }
         shutdownWithAction(
-          () => PromiseAll(ArrayPrototypeMap(actions, (action) => action())),
+          () =>
+            SafePromiseAll(ArrayPrototypeMap(actions, (action) => action())),
           true,
           error,
         );
diff --git a/ext/webgpu/src/01_webgpu.js b/ext/webgpu/src/01_webgpu.js
index caa103e625274..f4d15e2dd8432 100644
--- a/ext/webgpu/src/01_webgpu.js
+++ b/ext/webgpu/src/01_webgpu.js
@@ -27,12 +27,12 @@
     ObjectDefineProperty,
     ObjectPrototypeIsPrototypeOf,
     Promise,
-    PromiseAll,
     PromisePrototypeCatch,
     PromisePrototypeThen,
     PromiseReject,
     PromiseResolve,
     SafeArrayIterator,
+    SafePromiseAll,
     Set,
     SetPrototypeEntries,
     SetPrototypeForEach,
@@ -1517,7 +1517,7 @@
           "OperationError",
         );
       }
-      const operations = PromiseAll(scope.operations);
+      const operations = SafePromiseAll(scope.operations);
       return PromisePrototypeThen(
         operations,
         () => PromiseResolve(null),
diff --git a/runtime/js/40_spawn.js b/runtime/js/40_spawn.js
index a9a968ba32949..a927d619ed4c2 100644
--- a/runtime/js/40_spawn.js
+++ b/runtime/js/40_spawn.js
@@ -13,7 +13,8 @@
     String,
     TypeError,
     Uint8Array,
-    PromiseAll,
+    PromisePrototypeThen,
+    SafePromiseAll,
     SymbolFor,
   } = window.__bootstrap.primordials;
   const {
@@ -155,7 +156,7 @@
 
       const waitPromise = core.opAsync("op_spawn_wait", this.#rid);
       this.#waitPromiseId = waitPromise[promiseIdSymbol];
-      this.#status = waitPromise.then((res) => {
+      this.#status = PromisePrototypeThen(waitPromise, (res) => {
         this.#rid = null;
         signal?.[remove](onAbort);
         return res;
@@ -179,7 +180,7 @@
         );
       }
 
-      const [status, stdout, stderr] = await PromiseAll([
+      const [status, stdout, stderr] = await SafePromiseAll([
         this.#status,
         collectOutput(this.#stdout),
         collectOutput(this.#stderr),