diff --git a/client/util.c b/client/util.c
index b14023067..3c7ef4ba0 100644
--- a/client/util.c
+++ b/client/util.c
@@ -866,9 +866,18 @@ int num_CPUs(void) {
     SYSTEM_INFO sysinfo;
     GetSystemInfo(&sysinfo);
     return sysinfo.dwNumberOfProcessors;
-#elif defined(__linux__) || defined(__APPLE__)
+#elif defined(__linux__) && defined(_SC_NPROCESSORS_ONLN)
 #include <unistd.h>
-    return sysconf(_SC_NPROCESSORS_ONLN);
+    int count = sysconf(_SC_NPROCESSORS_ONLN);
+    if (count <= 0) 
+        count = 1;
+    return count;   
+#elif defined(__APPLE__)
+#include "sys/sysctl.h"
+    uint32 logicalcores = 0;
+    size_t size = sizeof( logicalcores );
+    sysctlbyname( "hw.logicalcpu", &logicalcores, &size, NULL, 0 );
+    return logicalcores;
 #else
     return 1;
 #endif