diff --git a/security/sandbox/linux/moz.build b/security/sandbox/linux/moz.build
--- a/security/sandbox/linux/moz.build
+++ b/security/sandbox/linux/moz.build
@@ -99,9 +99,8 @@
# gcc lto likes to put the top level asm in syscall.cc in a different partition
# 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':
- LDFLAGS += ['--param lto-partitions=1']
+if CONFIG['CC_TYPE'] != 'clang':
+ LDFLAGS += ['--param', 'lto-partitions=1']
DEFINES['NS_NO_XPCOM'] = True
DisableStlWrapping()