diff --git a/code/sys/sys_unix.c b/code/sys/sys_unix.c
index 2ed5f1b0f2..60f6e643c8 100644
--- a/code/sys/sys_unix.c
+++ b/code/sys/sys_unix.c
@@ -42,6 +42,15 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #include <time.h>
 #include <sys/resource.h>
 
+#if defined (__linux__)
+#include <sys/sysinfo.h>
+#endif
+
+#if defined (__FreeBSD__) || defined (__OpenBSD__) || defined (__APPLE__)
+#include <sys/sysctl.h>
+#include <sys/types.h>
+#endif
+
 qboolean stdinIsATTY;
 
 static char execBuffer[ 1024 ];
@@ -595,7 +604,33 @@ TODO
 */
 qboolean Sys_LowPhysicalMemory( void )
 {
+#if defined (__linux__)
+	struct sysinfo info;
+
+	if ( sysinfo(&info) == -1 )
+		return qfalse;
+
+	return info.totalram <= MEM_THRESHOLD;
+#elif defined (__FreeBSD__) || defined (__OpenBSD__) || defined (__APPLE__)
+        #if defined (__FreeBSD__)
+	int mib[2] = { CTL_HW, HW_PHYSMEM };
+        #elif defined (__OpenBSD__)
+	int mib[2] = { CTL_HW, HW_PHYSMEM64 };
+        #elif defined (__APPLE__)
+	int mib[2] = { CTL_HW, HW_MEMSIZE };
+        #endif
+
+	size_t len;
+	int64_t total_mem;
+
+	len = sizeof(int64_t);
+	if ( sysctl(mib, 2, &total_mem, &len, NULL, 0) == -1 )
+		return qfalse;
+
+	return total_mem <= MEM_THRESHOLD;
+#else
 	return qfalse;
+#endif
 }
 
 /*