diff --git a/compiler-rt/lib/scudo/standalone/linux.cpp b/compiler-rt/lib/scudo/standalone/linux.cpp
index 9b5ed67c515d..63a8e43b5bfb 100644
--- a/compiler-rt/lib/scudo/standalone/linux.cpp
+++ b/compiler-rt/lib/scudo/standalone/linux.cpp
@@ -96,7 +96,7 @@ static bool madviseNeedsMemset() {
                          MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
   if (!P)
     dieOnMapUnmapError(errno == ENOMEM);
-  *P = -1;
+  *P = 1;
   while (madvise(P, Size, MADV_DONTNEED) == -1 && errno == EAGAIN) {
   }
   bool R = (*P != 0);