diff --git a/dom/streams/ReadableByteStreamController.cpp b/dom/streams/ReadableByteStreamController.cpp
index 4645293dc7e7..32b5edb8f4f3 100644
--- a/dom/streams/ReadableByteStreamController.cpp
+++ b/dom/streams/ReadableByteStreamController.cpp
@@ -1895,10 +1895,8 @@ void SetUpReadableByteStreamController(
   }
 
   // Let startPromise be a promise resolved with startResult.
-  RefPtr<Promise> startPromise = Promise::Create(GetIncumbentGlobal(), aRv);
-  if (aRv.Failed()) {
-    return;
-  }
+  RefPtr<Promise> startPromise =
+      Promise::CreateInfallible(GetIncumbentGlobal());
   startPromise->MaybeResolve(startResult);
 
   // Step 16+17
diff --git a/dom/streams/ReadableStream.cpp b/dom/streams/ReadableStream.cpp
index 21870e0f7f2d..45046768cf5f 100644
--- a/dom/streams/ReadableStream.cpp
+++ b/dom/streams/ReadableStream.cpp
@@ -331,11 +331,8 @@ already_AddRefed<Promise> ReadableStreamCancel(JSContext* aCx,
 
   // Step 2.
   if (aStream->State() == ReadableStream::ReaderState::Closed) {
-    RefPtr<Promise> promise = Promise::Create(aStream->GetParentObject(), aRv);
-    if (aRv.Failed()) {
-      return nullptr;
-    }
-
+    RefPtr<Promise> promise =
+        Promise::CreateInfallible(aStream->GetParentObject());
     promise->MaybeResolveWithUndefined();
     return promise.forget();
   }
@@ -387,10 +384,7 @@ already_AddRefed<Promise> ReadableStreamCancel(JSContext* aCx,
 
   // Step 8.
   RefPtr<Promise> promise =
-      Promise::Create(sourceCancelPromise->GetParentObject(), aRv);
-  if (aRv.Failed()) {
-    return nullptr;
-  }
+      Promise::CreateInfallible(sourceCancelPromise->GetParentObject());
 
   // ThenWithCycleCollectedArgs will carry promise, keeping it alive until the
   // callback executes.
@@ -894,10 +888,7 @@ already_AddRefed<Promise> ReadableStream::GetNextIterationResult(
   MOZ_ASSERT(reader->GetStream());
 
   // Step 3. Let promise be a new promise.
-  RefPtr<Promise> promise = Promise::Create(GetParentObject(), aRv);
-  if (aRv.Failed()) {
-    return nullptr;
-  }
+  RefPtr<Promise> promise = Promise::CreateInfallible(GetParentObject());
 
   // Step 4. Let readRequest be a new read request with the following items:
   RefPtr<ReadRequest> request = new IteratorReadRequest(promise, reader);
diff --git a/dom/streams/ReadableStreamBYOBReader.cpp b/dom/streams/ReadableStreamBYOBReader.cpp
index b8281e204b45..6c615e03404d 100644
--- a/dom/streams/ReadableStreamBYOBReader.cpp
+++ b/dom/streams/ReadableStreamBYOBReader.cpp
@@ -255,10 +255,7 @@ already_AddRefed<Promise> ReadableStreamBYOBReader::Read(
   }
 
   // Step 5.
-  RefPtr<Promise> promise = Promise::Create(GetParentObject(), aRv);
-  if (aRv.Failed()) {
-    return nullptr;
-  }
+  RefPtr<Promise> promise = Promise::CreateInfallible(GetParentObject());
 
   // Step 6. Let readIntoRequest be a new read-into request with the following
   // items:
diff --git a/dom/streams/ReadableStreamDefaultController.cpp b/dom/streams/ReadableStreamDefaultController.cpp
index dda3ec75fc21..df8b2d7285bb 100644
--- a/dom/streams/ReadableStreamDefaultController.cpp
+++ b/dom/streams/ReadableStreamDefaultController.cpp
@@ -507,10 +507,7 @@ void SetUpReadableStreamDefaultController(
 
   // Step 10.
   RefPtr<Promise> startPromise =
-      Promise::Create(aStream->GetParentObject(), aRv);
-  if (aRv.Failed()) {
-    return;
-  }
+      Promise::CreateInfallible(aStream->GetParentObject());
   startPromise->MaybeResolve(startResult);
 
   // Step 11 & 12:
diff --git a/dom/streams/ReadableStreamDefaultReader.cpp b/dom/streams/ReadableStreamDefaultReader.cpp
index 218ef9f37bcc..014aca9652b7 100644
--- a/dom/streams/ReadableStreamDefaultReader.cpp
+++ b/dom/streams/ReadableStreamDefaultReader.cpp
@@ -67,10 +67,8 @@ bool ReadableStreamReaderGenericInitialize(ReadableStreamGenericReader* aReader,
   // Step 2.
   aStream->SetReader(aReader);
 
-  aReader->SetClosedPromise(Promise::Create(aReader->GetParentObject(), aRv));
-  if (aRv.Failed()) {
-    return false;
-  }
+  aReader->SetClosedPromise(
+      Promise::CreateInfallible(aReader->GetParentObject()));
 
   switch (aStream->State()) {
       // Step 3.
@@ -247,7 +245,7 @@ already_AddRefed<Promise> ReadableStreamDefaultReader::Read(ErrorResult& aRv) {
   }
 
   // Step 2.
-  RefPtr<Promise> promise = Promise::Create(GetParentObject(), aRv);
+  RefPtr<Promise> promise = Promise::CreateInfallible(GetParentObject());
 
   // Step 3.
   RefPtr<ReadRequest> request = new Read_ReadRequest(promise);
diff --git a/dom/streams/ReadableStreamPipeTo.cpp b/dom/streams/ReadableStreamPipeTo.cpp
index cbbaac43607e..71ddf6d190fe 100644
--- a/dom/streams/ReadableStreamPipeTo.cpp
+++ b/dom/streams/ReadableStreamPipeTo.cpp
@@ -941,10 +941,8 @@ already_AddRefed<Promise> ReadableStreamPipeTo(
   // Note: PipeToPump ensures this by construction.
 
   // Step 13. Let promise be a new promise.
-  RefPtr<Promise> promise = Promise::Create(aSource->GetParentObject(), aRv);
-  if (aRv.Failed()) {
-    return nullptr;
-  }
+  RefPtr<Promise> promise =
+      Promise::CreateInfallible(aSource->GetParentObject());
 
   // Steps 14-15.
   RefPtr<PipeToPump> pump = new PipeToPump(
diff --git a/dom/streams/TeeState.cpp b/dom/streams/TeeState.cpp
index 806107421ffa..349583977862 100644
--- a/dom/streams/TeeState.cpp
+++ b/dom/streams/TeeState.cpp
@@ -47,10 +47,7 @@ already_AddRefed<TeeState> TeeState::Create(ReadableStream* aStream,
   teeState->SetReader(reader);
 
   RefPtr<Promise> promise =
-      Promise::Create(teeState->GetStream()->GetParentObject(), aRv);
-  if (aRv.Failed()) {
-    return nullptr;
-  }
+      Promise::CreateInfallible(teeState->GetStream()->GetParentObject());
   teeState->SetCancelPromise(promise);
 
   return teeState.forget();
diff --git a/dom/streams/Transferable.cpp b/dom/streams/Transferable.cpp
index f436e5aa8ba0..c3aaa93a4be1 100644
--- a/dom/streams/Transferable.cpp
+++ b/dom/streams/Transferable.cpp
@@ -178,7 +178,8 @@ class SetUpTransformWritableMessageEventListener final
   Promise* BackpressurePromise() { return mBackpressurePromise; }
 
   void CreateBackpressurePromise(ErrorResult& aRv) {
-    mBackpressurePromise = Promise::Create(mController->GetParentObject(), aRv);
+    mBackpressurePromise =
+        Promise::CreateInfallible(mController->GetParentObject());
   }
 
  private:
@@ -449,10 +450,7 @@ MOZ_CAN_RUN_SCRIPT static void SetUpCrossRealmTransformWritable(
 
   // Step 3: Let backpressurePromise be a new promise.
   RefPtr<Promise> backpressurePromise =
-      Promise::Create(aWritable->GetParentObject(), aRv);
-  if (aRv.Failed()) {
-    return;
-  }
+      Promise::CreateInfallible(aWritable->GetParentObject());
 
   // Step 4: Add a handler for port’s message event with the following steps:
   auto listener = MakeRefPtr<SetUpTransformWritableMessageEventListener>(
diff --git a/dom/streams/TransformStream.cpp b/dom/streams/TransformStream.cpp
index 6765c1620c5b..6ec994529d2c 100644
--- a/dom/streams/TransformStream.cpp
+++ b/dom/streams/TransformStream.cpp
@@ -517,10 +517,7 @@ void TransformStream::SetBackpressure(bool aBackpressure, ErrorResult& aRv) {
   }
 
   // Step 3. Set stream.[[backpressureChangePromise]] to a new promise.
-  RefPtr<Promise> promise = Promise::Create(GetParentObject(), aRv);
-  if (aRv.Failed()) {
-    return;
-  }
+  RefPtr<Promise> promise = Promise::CreateInfallible(GetParentObject());
   mBackpressureChangePromise = promise;
 
   // Step 4. Set stream.[[backpressure]] to backpressure.
@@ -657,10 +654,7 @@ already_AddRefed<TransformStream> TransformStream::Constructor(
 
   // Step 9. Let startPromise be a new promise.
   nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aGlobal.GetAsSupports());
-  RefPtr<Promise> startPromise = Promise::Create(global, aRv);
-  if (aRv.Failed()) {
-    return nullptr;
-  }
+  RefPtr<Promise> startPromise = Promise::CreateInfallible(global);
 
   // Step 10. Perform ! InitializeTransformStream(this, startPromise,
   // writableHighWaterMark, writableSizeAlgorithm, readableHighWaterMark,
diff --git a/dom/streams/WritableStream.cpp b/dom/streams/WritableStream.cpp
index 8d10ff4836cb..e910e294544f 100644
--- a/dom/streams/WritableStream.cpp
+++ b/dom/streams/WritableStream.cpp
@@ -422,10 +422,8 @@ void WritableStream::UpdateBackpressure(bool aBackpressure, ErrorResult& aRv) {
     // Step 4.1. If backpressure is true, set writer.[[readyPromise]] to a new
     // promise.
     if (aBackpressure) {
-      RefPtr<Promise> promise = Promise::Create(writer->GetParentObject(), aRv);
-      if (aRv.Failed()) {
-        return;
-      }
+      RefPtr<Promise> promise =
+          Promise::CreateInfallible(writer->GetParentObject());
       writer->SetReadyPromise(promise);
     } else {
       // Step 4.2. Otherwise,
@@ -513,10 +511,8 @@ already_AddRefed<Promise> WritableStreamAbort(JSContext* aCx,
   // resolved with undefined.
   if (aStream->State() == WritableStream::WriterState::Closed ||
       aStream->State() == WritableStream::WriterState::Errored) {
-    RefPtr<Promise> promise = Promise::Create(aStream->GetParentObject(), aRv);
-    if (aRv.Failed()) {
-      return nullptr;
-    }
+    RefPtr<Promise> promise =
+        Promise::CreateInfallible(aStream->GetParentObject());
     promise->MaybeResolveWithUndefined();
     return promise.forget();
   }
@@ -533,10 +529,8 @@ already_AddRefed<Promise> WritableStreamAbort(JSContext* aCx,
   // code and that might have changed the state.
   if (aStream->State() == WritableStream::WriterState::Closed ||
       aStream->State() == WritableStream::WriterState::Errored) {
-    RefPtr<Promise> promise = Promise::Create(aStream->GetParentObject(), aRv);
-    if (aRv.Failed()) {
-      return nullptr;
-    }
+    RefPtr<Promise> promise =
+        Promise::CreateInfallible(aStream->GetParentObject());
     promise->MaybeResolveWithUndefined();
     return promise.forget();
   }
@@ -565,10 +559,8 @@ already_AddRefed<Promise> WritableStreamAbort(JSContext* aCx,
   }
 
   // Step 9. Let promise be a new promise.
-  RefPtr<Promise> promise = Promise::Create(aStream->GetParentObject(), aRv);
-  if (aRv.Failed()) {
-    return nullptr;
-  }
+  RefPtr<Promise> promise =
+      Promise::CreateInfallible(aStream->GetParentObject());
 
   // Step 10. Set stream.[[pendingAbortRequest]] to a new pending abort request
   // whose promise is promise, reason is reason, and was already erroring is
@@ -628,10 +620,8 @@ already_AddRefed<Promise> WritableStreamClose(JSContext* aCx,
   MOZ_ASSERT(!aStream->CloseQueuedOrInFlight());
 
   // Step 5. Let promise be a new promise.
-  RefPtr<Promise> promise = Promise::Create(aStream->GetParentObject(), aRv);
-  if (aRv.Failed()) {
-    return nullptr;
-  }
+  RefPtr<Promise> promise =
+      Promise::CreateInfallible(aStream->GetParentObject());
 
   // Step 6. Set stream.[[closeRequest]] to promise.
   aStream->SetCloseRequest(promise);
@@ -742,10 +732,8 @@ already_AddRefed<Promise> WritableStreamAddWriteRequest(WritableStream* aStream,
   MOZ_ASSERT(aStream->State() == WritableStream::WriterState::Writable);
 
   // Step 3. Let promise be a new promise.
-  RefPtr<Promise> promise = Promise::Create(aStream->GetParentObject(), aRv);
-  if (aRv.Failed()) {
-    return nullptr;
-  }
+  RefPtr<Promise> promise =
+      Promise::CreateInfallible(aStream->GetParentObject());
 
   // Step 4. Append promise to stream.[[writeRequests]].
   aStream->AppendWriteRequest(promise);
diff --git a/dom/streams/WritableStreamDefaultController.cpp b/dom/streams/WritableStreamDefaultController.cpp
index 32099f8f3974..2f0964bc8f24 100644
--- a/dom/streams/WritableStreamDefaultController.cpp
+++ b/dom/streams/WritableStreamDefaultController.cpp
@@ -184,10 +184,7 @@ void SetUpWritableStreamDefaultController(
 
   // Step 16. Let startPromise be a promise resolved with startResult.
   RefPtr<Promise> startPromise =
-      Promise::Create(aStream->GetParentObject(), aRv);
-  if (aRv.Failed()) {
-    return;
-  }
+      Promise::CreateInfallible(aStream->GetParentObject());
   startPromise->MaybeResolve(startResult);
 
   // Step 17/18.
diff --git a/dom/streams/WritableStreamDefaultWriter.cpp b/dom/streams/WritableStreamDefaultWriter.cpp
index c7f1186ce799..b3728420e890 100644
--- a/dom/streams/WritableStreamDefaultWriter.cpp
+++ b/dom/streams/WritableStreamDefaultWriter.cpp
@@ -382,10 +382,7 @@ void SetUpWritableStreamDefaultWriter(WritableStreamDefaultWriter* aWriter,
   // Step 5. If state is "writable",
   if (state == WritableStream::WriterState::Writable) {
     RefPtr<Promise> readyPromise =
-        Promise::Create(aWriter->GetParentObject(), aRv);
-    if (aRv.Failed()) {
-      return;
-    }
+        Promise::CreateInfallible(aWriter->GetParentObject());
 
     // Step 5.1 If ! WritableStreamCloseQueuedOrInFlight(stream) is false and
     // stream.[[backpressure]] is true, set writer.[[readyPromise]] to a new
@@ -401,10 +398,7 @@ void SetUpWritableStreamDefaultWriter(WritableStreamDefaultWriter* aWriter,
 
     // Step 5.3. Set writer.[[closedPromise]] to a new promise.
     RefPtr<Promise> closedPromise =
-        Promise::Create(aWriter->GetParentObject(), aRv);
-    if (aRv.Failed()) {
-      return;
-    }
+        Promise::CreateInfallible(aWriter->GetParentObject());
     aWriter->SetClosedPromise(closedPromise);
   } else if (state == WritableStream::WriterState::Erroring) {
     // Step 6. Otherwise, if state is "erroring",
@@ -413,10 +407,7 @@ void SetUpWritableStreamDefaultWriter(WritableStreamDefaultWriter* aWriter,
     // stream.[[storedError]].
     JS::Rooted<JS::Value> storedError(RootingCx(), aStream->StoredError());
     RefPtr<Promise> readyPromise =
-        Promise::Create(aWriter->GetParentObject(), aRv);
-    if (aRv.Failed()) {
-      return;
-    }
+        Promise::CreateInfallible(aWriter->GetParentObject());
     readyPromise->MaybeReject(storedError);
     aWriter->SetReadyPromise(readyPromise);
 
@@ -425,10 +416,7 @@ void SetUpWritableStreamDefaultWriter(WritableStreamDefaultWriter* aWriter,
 
     // Step 6.3. Set writer.[[closedPromise]] to a new promise.
     RefPtr<Promise> closedPromise =
-        Promise::Create(aWriter->GetParentObject(), aRv);
-    if (aRv.Failed()) {
-      return;
-    }
+        Promise::CreateInfallible(aWriter->GetParentObject());
     aWriter->SetClosedPromise(closedPromise);
   } else if (state == WritableStream::WriterState::Closed) {
     // Step 7. Otherwise, if state is "closed",
@@ -460,10 +448,7 @@ void SetUpWritableStreamDefaultWriter(WritableStreamDefaultWriter* aWriter,
     // Step 8.3. Set writer.[[readyPromise]] to a promise rejected with
     // storedError.
     RefPtr<Promise> readyPromise =
-        Promise::Create(aWriter->GetParentObject(), aRv);
-    if (aRv.Failed()) {
-      return;
-    }
+        Promise::CreateInfallible(aWriter->GetParentObject());
     readyPromise->MaybeReject(storedError);
     aWriter->SetReadyPromise(readyPromise);
 
@@ -473,10 +458,7 @@ void SetUpWritableStreamDefaultWriter(WritableStreamDefaultWriter* aWriter,
     // Step 8.5. Set writer.[[closedPromise]] to a promise rejected with
     // storedError.
     RefPtr<Promise> closedPromise =
-        Promise::Create(aWriter->GetParentObject(), aRv);
-    if (aRv.Failed()) {
-      return;
-    }
+        Promise::CreateInfallible(aWriter->GetParentObject());
     closedPromise->MaybeReject(storedError);
     aWriter->SetClosedPromise(closedPromise);
 
@@ -497,10 +479,7 @@ void WritableStreamDefaultWriterEnsureClosedPromiseRejected(
   } else {
     // Step 2. Otherwise, set writer.[[closedPromise]] to a promise rejected
     // with error.
-    closedPromise = Promise::Create(aWriter->GetParentObject(), aRv);
-    if (aRv.Failed()) {
-      return;
-    }
+    closedPromise = Promise::CreateInfallible(aWriter->GetParentObject());
     closedPromise->MaybeReject(aError);
     aWriter->SetClosedPromise(closedPromise);
   }
@@ -521,10 +500,7 @@ void WritableStreamDefaultWriterEnsureReadyPromiseRejected(
   } else {
     // Step 2. Otherwise, set writer.[[readyPromise]] to a promise rejected with
     // error.
-    readyPromise = Promise::Create(aWriter->GetParentObject(), aRv);
-    if (aRv.Failed()) {
-      return;
-    }
+    readyPromise = Promise::CreateInfallible(aWriter->GetParentObject());
     readyPromise->MaybeReject(aError);
     aWriter->SetReadyPromise(readyPromise);
   }