diff --git a/libc/bionic/strsignal.cpp b/libc/bionic/strsignal.cpp
index 81a8f95..1cdfec1 100644
--- a/libc/bionic/strsignal.cpp
+++ b/libc/bionic/strsignal.cpp
@@ -36,7 +36,7 @@
 char* strsignal(int signal_number) {
   // Just return the original constant in the easy cases.
   char* result = const_cast<char*>(__strsignal_lookup(signal_number));
-  if (result != NULL) {
+  if (result != nullptr) {
     return result;
   }