diff --git a/libs/binder/OS_android.cpp b/libs/binder/OS_android.cpp
index 155588d..1eace85 100644
--- a/libs/binder/OS_android.cpp
+++ b/libs/binder/OS_android.cpp
@@ -20,7 +20,8 @@
 #include <cutils/trace.h>
 #include <utils/misc.h>
 
-namespace android::binder::os {
+namespace android::binder {
+namespace os {
 
 uint64_t GetThreadId() {
 #ifdef BINDER_RPC_SINGLE_THREADED
@@ -43,4 +44,16 @@
     atrace_end(tag);
 }
 
-} // namespace android::binder::os
+} // namespace os
+
+// Legacy trace symbol. To be removed once all of downstream rebuilds.
+void atrace_begin(uint64_t tag, const char* name) {
+    os::trace_begin(tag, name);
+}
+
+// Legacy trace symbol. To be removed once all of downstream rebuilds.
+void atrace_end(uint64_t tag) {
+    os::trace_end(tag);
+}
+
+} // namespace android::binder