diff --git a/src/common/system.cpp b/src/common/system.cpp
index cf032adfced..35a6f4415bc 100644
--- a/src/common/system.cpp
+++ b/src/common/system.cpp
@@ -113,10 +113,15 @@ int GetNumCores()
 
 std::optional<size_t> GetTotalRAM()
 {
-    auto clamp{[](uint64_t v) { return size_t(std::min(v, uint64_t{std::numeric_limits<size_t>::max()})); }};
+    [[maybe_unused]] auto clamp{[](uint64_t v) { return size_t(std::min(v, uint64_t{std::numeric_limits<size_t>::max()})); }};
 #ifdef WIN32
     if (MEMORYSTATUSEX m{}; (m.dwLength = sizeof(m), GlobalMemoryStatusEx(&m))) return clamp(m.ullTotalPhys);
-#elif defined(__linux__) || defined(__APPLE__)
+#elif defined(__APPLE__) || \
+      defined(__FreeBSD__) || \
+      defined(__NetBSD__) || \
+      defined(__OpenBSD__) || \
+      defined(__illumos__) || \
+      defined(__linux__)
     if (long p{sysconf(_SC_PHYS_PAGES)}, s{sysconf(_SC_PAGESIZE)}; p > 0 && s > 0) return clamp(1ULL * p * s);
 #endif
     return std::nullopt;