diff --git a/arm/config/compiler/BUILD.gn b/arm/config/compiler/BUILD.gn
index 9b10c51d..3aff1925 100644
--- a/arm/config/compiler/BUILD.gn
+++ b/arm/config/compiler/BUILD.gn
@@ -901,11 +901,6 @@ config("compiler_cpu_abi") {
           "-msse3",
         ]
       }
-    } else if (target_cpu == "arm64") {
-      if (!is_android && !is_nacl) {
-        cflags += [ "-O3", "-Wno-unused-command-line-argument", ]
-        ldflags += [ "-Wl,-O3", "-Wno-unused-command-line-argument", ]
-      }
     } else if (current_cpu == "arm") {
       if (is_clang && !is_android && !is_nacl &&
           !(is_chromeos_lacros && is_chromeos_device)) {