diff --git a/libc-top-half/musl/src/signal/psignal.c b/libc-top-half/musl/src/signal/psignal.c
index aa49ae06..5b9dc38f 100644
--- a/libc-top-half/musl/src/signal/psignal.c
+++ b/libc-top-half/musl/src/signal/psignal.c
@@ -3,10 +3,12 @@
 #include <signal.h>
 #include <errno.h>
 
+#ifndef __wasilibc_unmodified_upstream
 /* undef the macro to use the standard stderr instead of __stderr_FILE
  * (the libc internal symbol) as this lives in a separate library,
  * libwasi-emulated-signal.so. */
 #undef stderr
+#endif
 
 void psignal(int sig, const char *msg)
 {