diff --git a/src/mem/physical.cc b/src/mem/physical.cc
index 84af4c752..7337c800c 100644
--- a/src/mem/physical.cc
+++ b/src/mem/physical.cc
@@ -90,7 +90,7 @@ PhysicalMemory::PhysicalMemory(const Params *p)
         int fd = open(params()->file.c_str(), O_RDONLY);
         _size = lseek(fd, 0, SEEK_END);
         lseek(fd, 0, SEEK_SET);
-        pmemAddr = (uint8_t *)mmap(NULL, roundUp(size(), PAGE_SIZE),
+        pmemAddr = (uint8_t *)mmap(NULL, roundUp(size(), sysconf(_SC_PAGESIZE)),
                                    PROT_READ | PROT_WRITE, map_flags, fd, 0);
     }