--- src/apple/ram.cpp	2026-07-01 06:43:12.000000000 +0800
+++ src/apple/ram.cpp	2026-07-01 18:09:30.000000000 +0800
@@ -10,6 +10,7 @@
 #include <mach/mach_init.h>
 #include <mach/vm_statistics.h>
 #include <sys/sysctl.h>
+#include <AvailabilityMacros.h>
 
 #include <string>
 
@@ -34,24 +34,28 @@
 
 // _____________________________________________________________________________________________________________________
 uint64_t Memory::size() const {
-  uint64_t sum = 0;
-  for (const auto& module : _modules) {
-    sum += module._size_bytes;
+  // If module info is not populated, fall back to the system total.
+  if (!_modules.empty()) {
+    uint64_t sum = 0;
+    for (const auto& module : _modules) {
+      sum += module._size_bytes;
+    }
+    return sum;
   }
-  return sum;
+  return getMemSize();
 }
 
 // _____________________________________________________________________________________________________________________
 uint64_t Memory::free() const {
+  vm_size_t pageSize;
+  host_page_size(mach_host_self(), &pageSize);
+#if MAC_OS_X_VERSION_MIN_REQUIRED >= 1060 && !defined(__i386__) && !defined(__ppc__)
   vm_statistics64_data_t vmStats;
   mach_msg_type_number_t infoCount = HOST_VM_INFO64_COUNT;
   kern_return_t kernReturn =
       host_statistics64(mach_host_self(), HOST_VM_INFO64, reinterpret_cast<host_info64_t>(&vmStats), &infoCount);
 
   if (kernReturn == KERN_SUCCESS) {
-    vm_size_t pageSize;
-    host_page_size(mach_host_self(), &pageSize);
-
     int64_t totalMemory = getMemSize();
     if (totalMemory == -1) return -1;
 
@@ -64,18 +76,40 @@
     const int64_t usedMemory = appMemory + wiredMemory + compressedMemory;
     return totalMemory - usedMemory;
   }
+#else
+  vm_statistics_data_t vmStats;
+  mach_msg_type_number_t infoCount = HOST_VM_INFO_COUNT;
+  kern_return_t kernReturn =
+      host_statistics(mach_host_self(), HOST_VM_INFO, reinterpret_cast<host_info_t>(&vmStats), &infoCount);
+
+  if (kernReturn == KERN_SUCCESS) {
+    return static_cast<uint64_t>(vmStats.free_count) * static_cast<uint64_t>(pageSize);
+  }
+#endif
 
   return 0;
 }
 
 // _____________________________________________________________________________________________________________________
 uint64_t Memory::available() const {
+#if MAC_OS_X_VERSION_MIN_REQUIRED < 1060 || defined(__i386__) || defined(__ppc__)
+  vm_size_t pageSize;
+  host_page_size(mach_host_self(), &pageSize);
+  vm_statistics_data_t vmStats;
+  mach_msg_type_number_t infoCount = HOST_VM_INFO_COUNT;
+
+  if (host_statistics(mach_host_self(), HOST_VM_INFO,
+                      reinterpret_cast<host_info_t>(&vmStats), &infoCount) == KERN_SUCCESS) {
+    return static_cast<uint64_t>(vmStats.free_count + vmStats.inactive_count) * static_cast<uint64_t>(pageSize);
+  }
+#else
   int64_t usableMemSize;
   size_t size = sizeof(usableMemSize);
 
   if (sysctlbyname("hw.memsize_usable", &usableMemSize, &size, nullptr, 0) == 0) {
     return usableMemSize;
   }
+#endif
 
   return 0;
 }