diff --git a/src/common_define.h b/src/common_define.h
index 3ecc508..8681c19 100644
--- a/src/common_define.h
+++ b/src/common_define.h
@@ -153,6 +153,10 @@ extern int pthread_mutexattr_settype(pthread_mutexattr_t *attr, int kind);
 #define ECANCELED 125
 #endif
 
+#ifndef ENODATA
+#define ENODATA         61      /* No data available */
+#endif
+
 #ifndef ENONET
 #define ENONET          64      /* Machine is not on the network */
 #endif
diff --git a/src/system_info.c b/src/system_info.c
index 5618b89..2fc5ff9 100644
--- a/src/system_info.c
+++ b/src/system_info.c
@@ -72,8 +72,11 @@ int get_sys_total_mem_size(int64_t *mem_size)
    size_t len;
 
    mib[0] = CTL_HW;
-   //mib[1] = HW_MEMSIZE;
+#ifdef DARWIN
+   mib[1] = HW_MEMSIZE;
+#else
    mib[1] = HW_PHYSMEM;
+#endif
    len = sizeof(*mem_size);
    if (sysctl(mib, 2, mem_size, &len, NULL, 0) != 0)
    {