diff --git a/libc/bionic/__libc_current_sigrtmax.cpp b/libc/bionic/__libc_current_sigrtmax.cpp
index 27fcb35..32179bb 100644
--- a/libc/bionic/__libc_current_sigrtmax.cpp
+++ b/libc/bionic/__libc_current_sigrtmax.cpp
@@ -29,5 +29,7 @@
 #include <signal.h>
 
 int __libc_current_sigrtmax(void) {
+  // If you change this, also change __ndk_legacy___libc_current_sigrtmax
+  // in <android/legacy_signal_inlines.h> to match.
   return __SIGRTMAX;
 }
diff --git a/libc/bionic/__libc_current_sigrtmin.cpp b/libc/bionic/__libc_current_sigrtmin.cpp
index 7c93267..f3b2bf6 100644
--- a/libc/bionic/__libc_current_sigrtmin.cpp
+++ b/libc/bionic/__libc_current_sigrtmin.cpp
@@ -34,5 +34,7 @@
 // __SIGRTMIN + 3 is reserved for triggering native stack dumps.
 
 int __libc_current_sigrtmin(void) {
+  // If you change this, also change __ndk_legacy___libc_current_sigrtmin
+  // in <android/legacy_signal_inlines.h> to match.
   return __SIGRTMIN + 4;
 }