--- a/browser/config/mozconfigs/linux32/valgrind
+++ b/browser/config/mozconfigs/linux32/valgrind
@@ -1,9 +1,10 @@
 . $topsrcdir/browser/config/mozconfigs/linux32/nightly
 
 ac_add_options --enable-valgrind
 ac_add_options --disable-jemalloc
 ac_add_options --disable-install-strip
+ac_add_options --disable-gtest-in-build
 
 # Include the override mozconfig again (even though the above includes it)
 # since it's supposed to override everything.
 . "$topsrcdir/build/mozconfig.common.override"

--- a/browser/config/mozconfigs/linux64/valgrind
+++ b/browser/config/mozconfigs/linux64/valgrind
@@ -1,9 +1,10 @@
 . $topsrcdir/browser/config/mozconfigs/linux64/nightly
 
 ac_add_options --enable-valgrind
 ac_add_options --disable-jemalloc
 ac_add_options --disable-install-strip
+ac_add_options --disable-gtest-in-build
 
 # Include the override mozconfig again (even though the above includes it)
 # since it's supposed to override everything.
 . "$topsrcdir/build/mozconfig.common.override"

--- a/moz.configure
+++ b/moz.configure
@@ -152,22 +152,28 @@ option('--build-backends', nargs='+', de
        choices=build_backends_choices, help='Build backends to generate')
 
 @depends('--build-backends')
 def build_backends(backends):
     return backends
 
 set_config('BUILD_BACKENDS', build_backends)
 
+option('--disable-gtest-in-build',
+       help='Force disable building the gtest libxul during the build.',
+       when='--enable-compile-environment')
+
 # Determine whether to build the gtest xul. This happens in automation
 # on Desktop platforms with the exception of Windows PGO, where linking
 # xul-gtest.dll takes too long.
-@depends('MOZ_PGO', build_project, target, 'MOZ_AUTOMATION',
+@depends('MOZ_PGO', build_project, target, 'MOZ_AUTOMATION', '--disable-gtest-in-build',
          when='--enable-compile-environment')
-def build_gtest(pgo, build_project, target, automation):
+def build_gtest(pgo, build_project, target, automation, enabled):
+    if not enabled:
+        return None
     if (automation and build_project == 'browser' and
         not (pgo and target.os == 'WINNT')):
         return True
 
 set_config('LINK_GTEST_DURING_COMPILE', build_gtest)
 
 # Awk detection
 # ==============================================================