diff --git a/js/src/make-source-package.sh b/js/src/make-source-package.sh
index 812da53e8e05..82e99a99ffa3 100755
--- a/js/src/make-source-package.sh
+++ b/js/src/make-source-package.sh
@@ -94,7 +94,6 @@ case $cmd in
     cp -pPR \
         ${TOPSRCDIR}/memory/moz.build \
         ${TOPSRCDIR}/memory/build \
-        ${TOPSRCDIR}/memory/fallible \
         ${TOPSRCDIR}/memory/mozalloc \
         ${tgtpath}/memory/
 
diff --git a/memory/fallible/moz.build b/memory/fallible/moz.build
deleted file mode 100644
index 19539dec070e..000000000000
--- a/memory/fallible/moz.build
+++ /dev/null
@@ -1,9 +0,0 @@
-# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
-# vim: set filetype=python:
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-EXPORTS.mozilla += [
-    'fallible.h',
-]
diff --git a/memory/moz.build b/memory/moz.build
index d65eb565f35f..18b2999e3ebd 100644
--- a/memory/moz.build
+++ b/memory/moz.build
@@ -9,7 +9,6 @@ with Files("**"):
 
 DIRS += [
     'build',
-    'fallible',
 ]
 
 # For now, don't build mozalloc when building with --enable-project=memory
diff --git a/memory/fallible/fallible.h b/mfbt/fallible.h
similarity index 100%
rename from memory/fallible/fallible.h
rename to mfbt/fallible.h
diff --git a/mfbt/moz.build b/mfbt/moz.build
index a12c9c890781..aa36b32c9a22 100644
--- a/mfbt/moz.build
+++ b/mfbt/moz.build
@@ -38,6 +38,7 @@ EXPORTS.mozilla = [
     'EnumeratedRange.h',
     'EnumSet.h',
     'EnumTypeTraits.h',
+    'fallible.h',
     'FastBernoulliTrial.h',
     'FloatingPoint.h',
     'FStream.h',