diff --git a/compiler-rt/lib/fuzzer/FuzzerUtil.h b/compiler-rt/lib/fuzzer/FuzzerUtil.h
--- a/compiler-rt/lib/fuzzer/FuzzerUtil.h
+++ b/compiler-rt/lib/fuzzer/FuzzerUtil.h
@@ -16,6 +16,10 @@
 #include "FuzzerCommand.h"
 #include "FuzzerDefs.h"
 
+#if SANITIZER_USE_GETAUXVAL
+#include <sys/auxv.h>
+#endif
+
 namespace fuzzer {
 
 void PrintHexArray(const Unit &U, const char *PrintAfter = "");
@@ -94,7 +98,14 @@
   return static_cast<size_t>((sizeof(unsigned long long) * 8) - Clzll(X) - 1);
 }
 
-inline size_t PageSize() { return 4096; }
+inline size_t PageSize() {
+#if SANITIZER_USE_GETAUXVAL
+  return getauxval(AT_PAGESZ);
+#else
+  return 4096;
+#endif
+}
+
 inline uint8_t *RoundUpByPage(uint8_t *P) {
   uintptr_t X = reinterpret_cast<uintptr_t>(P);
   size_t Mask = PageSize() - 1;