--- a/security/sandbox/linux/moz.build	2019-07-11 15:29:41.211281893 +0200
+++ b/security/sandbox/linux/moz.build	2019-07-11 15:40:24.189355910 +0200
@@ -99,7 +99,7 @@
 # from the function using it which breaks the build.  Work around that by
 # forcing there to be only one partition.
 for f in CONFIG['OS_CXXFLAGS']:
-    if f.startswith('-flto') and CONFIG['CC_TYPE'] != 'clang':
+    if (f.startswith('-flto') or CONFIG['MOZ_LTO']) and CONFIG['CC_TYPE'] != 'clang':
         LDFLAGS += ['--param', 'lto-partitions=1']
 
 DEFINES['NS_NO_XPCOM'] = True