diff --git a/dom/indexedDB/ActorsParent.cpp b/dom/indexedDB/ActorsParent.cpp
index 806873444f21..b6f67edcc750 100644
--- a/dom/indexedDB/ActorsParent.cpp
+++ b/dom/indexedDB/ActorsParent.cpp
@@ -17243,7 +17243,7 @@ void QuotaClient::StopIdleMaintenance() {
     mCurrentMaintenance->Abort();
   }
 
-  for (RefPtr<Maintenance>& maintenance : mMaintenanceQueue) {
+  for (const auto& maintenance : mMaintenanceQueue) {
     maintenance->Abort();
   }
 }
@@ -23082,7 +23082,7 @@ void TransactionBase::CommitOp::CommitOrRollbackAutoIncrementCounts() {
              mTransaction->GetMode() == IDBTransaction::Mode::Cleanup ||
              mTransaction->GetMode() == IDBTransaction::Mode::VersionChange);
 
-  nsTArray<RefPtr<FullObjectStoreMetadata>>& metadataArray =
+  const auto& metadataArray =
       mTransaction->mModifiedAutoIncrementObjectStoreMetadataArray;
 
   if (!metadataArray.IsEmpty()) {
diff --git a/dom/indexedDB/IDBDatabase.cpp b/dom/indexedDB/IDBDatabase.cpp
index 74338d5b545d..5921f5061445 100644
--- a/dom/indexedDB/IDBDatabase.cpp
+++ b/dom/indexedDB/IDBDatabase.cpp
@@ -746,7 +746,7 @@ void IDBDatabase::AbortTransactions(bool aShouldWarn) {
       // additional strong references here.
       WeakTransactionArray transactionsThatNeedWarning;
 
-      for (RefPtr<IDBTransaction>& transaction : transactionsToAbort) {
+      for (const auto& transaction : transactionsToAbort) {
         MOZ_ASSERT(transaction);
         MOZ_ASSERT(!transaction->IsFinished());
 
diff --git a/dom/indexedDB/IDBMutableFile.cpp b/dom/indexedDB/IDBMutableFile.cpp
index 018a0ce597f7..b6e5e4f76f10 100644
--- a/dom/indexedDB/IDBMutableFile.cpp
+++ b/dom/indexedDB/IDBMutableFile.cpp
@@ -115,7 +115,7 @@ void IDBMutableFile::AbortFileHandles() {
   class MOZ_STACK_CLASS Helper final {
    public:
     static void AbortFileHandles(
-        nsTHashtable<nsPtrHashKey<IDBFileHandle>>& aTable) {
+        const nsTHashtable<nsPtrHashKey<IDBFileHandle>>& aTable) {
       if (!aTable.Count()) {
         return;
       }
@@ -123,8 +123,8 @@ void IDBMutableFile::AbortFileHandles() {
       nsTArray<RefPtr<IDBFileHandle>> fileHandlesToAbort;
       fileHandlesToAbort.SetCapacity(aTable.Count());
 
-      for (auto iter = aTable.Iter(); !iter.Done(); iter.Next()) {
-        IDBFileHandle* fileHandle = iter.Get()->GetKey();
+      for (auto iter = aTable.ConstIter(); !iter.Done(); iter.Next()) {
+        IDBFileHandle* const fileHandle = iter.Get()->GetKey();
         MOZ_ASSERT(fileHandle);
 
         fileHandle->AssertIsOnOwningThread();
@@ -139,7 +139,7 @@ void IDBMutableFile::AbortFileHandles() {
         return;
       }
 
-      for (RefPtr<IDBFileHandle>& fileHandle : fileHandlesToAbort) {
+      for (const auto& fileHandle : fileHandlesToAbort) {
         MOZ_ASSERT(fileHandle);
 
         fileHandle->Abort();