--- a/xpcom/ds/nsTArray.h
+++ b/xpcom/ds/nsTArray.h
@@ -13,16 +13,17 @@
 #include "mozilla/Assertions.h"
 #include "mozilla/Attributes.h"
 #include "mozilla/BinarySearch.h"
 #include "mozilla/CheckedInt.h"
 #include "mozilla/fallible.h"
 #include "mozilla/MathAlgorithms.h"
 #include "mozilla/MemoryReporting.h"
 #include "mozilla/Move.h"
+#include "mozilla/mozalloc.h"
 #include "mozilla/ReverseIterator.h"
 #include "mozilla/TypeTraits.h"
 #include "mozilla/Span.h"
 
 #include <string.h>
 
 #include "nsCycleCollectionNoteChild.h"
 #include "nsAlgorithm.h"

--- a/xpcom/string/nsTStringRepr.h
+++ b/xpcom/string/nsTStringRepr.h
@@ -5,16 +5,17 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #ifndef nsTStringRepr_h
 #define nsTStringRepr_h
 
 #include <type_traits> // std::enable_if
 
 #include "mozilla/Char16.h"
+#include "mozilla/fallible.h"
 #include "nsStringFlags.h"
 #include "nsCharTraits.h"
 
 template <typename T> class nsTSubstringTuple;
 template <typename T> class nsTLiteralString;
 
 // The base for string comparators
 template <typename T> class nsTStringComparator