--- a/python/mozbuild/mozbuild/backend/recursivemake.py
+++ b/python/mozbuild/mozbuild/backend/recursivemake.py
@@ -6,16 +6,17 @@ from __future__ import unicode_literals
 
 import errno
 import logging
 import os
 import types
 
 from collections import namedtuple
 
+import mozbuild.makeutil as mozmakeutil
 from mozpack.copier import FilePurger
 from mozpack.manifests import (
     InstallManifest,
 )
 import mozpack.path as mozpath
 
 from .common import CommonBackend
 from ..frontend.data import (
@@ -549,31 +550,35 @@ class RecursiveMakeBackend(CommonBackend
 
             self._update_from_avoid_write(bf.close())
             self.summary.managed_count += 1
 
 
         # Write out a master list of all IPDL source files.
         ipdls = FileAvoidWrite(os.path.join(self.environment.topobjdir,
             'ipc', 'ipdl', 'ipdlsrcs.mk'))
+        mk = mozmakeutil.Makefile()
+
         for p in sorted(self._ipdl_sources):
-            ipdls.write('ALL_IPDLSRCS += %s\n' % p)
+            mk.add_statement('ALL_IPDLSRCS += %s\n' % p)
             base = os.path.basename(p)
             root, ext = os.path.splitext(base)
 
             # Both .ipdl and .ipdlh become .cpp files
-            ipdls.write('CPPSRCS += %s.cpp\n' % root)
+            mk.add_statement('CPPSRCS += %s.cpp\n' % root)
             if ext == '.ipdl':
                 # .ipdl also becomes Child/Parent.cpp files
-                ipdls.write('CPPSRCS += %sChild.cpp\n' % root)
-                ipdls.write('CPPSRCS += %sParent.cpp\n' % root)
+                mk.add_statement('CPPSRCS += %sChild.cpp\n' % root)
+                mk.add_statement('CPPSRCS += %sParent.cpp\n' % root)
 
-        ipdls.write('IPDLDIRS := %s\n' % ' '.join(sorted(set(os.path.dirname(p)
+        mk.add_statement('IPDLDIRS := %s\n' % ' '.join(sorted(set(os.path.dirname(p)
             for p in self._ipdl_sources))))
 
+        mk.dump(ipdls)
+
         self._update_from_avoid_write(ipdls.close())
         self.summary.managed_count += 1
 
         # Write out master lists of WebIDL source files.
         webidls = FileAvoidWrite(os.path.join(self.environment.topobjdir,
               'dom', 'bindings', 'webidlsrcs.mk'))
 
         for webidl in sorted(self._webidl_sources):