diff --git a/compiler-rt/test/lsan/TestCases/Linux/leak_check_segv.cpp b/compiler-rt/test/lsan/TestCases/Linux/leak_check_segv.cpp
--- a/compiler-rt/test/lsan/TestCases/Linux/leak_check_segv.cpp
+++ b/compiler-rt/test/lsan/TestCases/Linux/leak_check_segv.cpp
@@ -5,14 +5,16 @@
 #include <stdio.h>
 #include <sys/mman.h>
 #include <sanitizer/lsan_interface.h>
+#include <unistd.h>
 
 char data[10 * 1024 * 1024];
 
 int main() {
+  long pagesize_mask = sysconf(_SC_PAGESIZE) - 1;
   void *p = malloc(10 * 1024 * 1024);
   // surprise-surprise!
-  mprotect((void*)(((unsigned long)p + 4095) & ~4095), 16 * 1024, PROT_NONE);
-  mprotect((void*)(((unsigned long)data + 4095) & ~4095), 16 * 1024, PROT_NONE);
+  mprotect((void*)(((unsigned long)p + pagesize_mask) & ~pagesize_mask), 16 * 1024, PROT_NONE);
+  mprotect((void*)(((unsigned long)data + pagesize_mask) & ~pagesize_mask), 16 * 1024, PROT_NONE);
   __lsan_do_leak_check();
   fprintf(stderr, "DONE\n");
 }