diff --git a/indra/newview/llappviewermacosx.cpp b/indra/newview/llappviewermacosx.cpp
index 9a00bdf481965d62e272c2ba719ea08211081089..045bc2dbf3f45ea28ed7a32c70430f384ef12b3e 100644
--- a/indra/newview/llappviewermacosx.cpp
+++ b/indra/newview/llappviewermacosx.cpp
@@ -394,7 +394,7 @@ std::string LLAppViewerMacOSX::generateSerialNumber()
 
 	// JC: Sample code from http://developer.apple.com/technotes/tn/tn1103.html
 	CFStringRef serialNumber = NULL;
-	io_service_t    platformExpert = IOServiceGetMatchingService(kIOMasterPortDefault,
+    io_service_t    platformExpert = IOServiceGetMatchingService(kIOMainPortDefault,
 																 IOServiceMatching("IOPlatformExpertDevice"));
 	if (platformExpert)
     {
diff --git a/indra/newview/llmachineid.cpp b/indra/newview/llmachineid.cpp
index c3b193876eb774f633154740e0407ced283c6524..eebe8ae80c9efd7a846d78b3a1894d69e0bbcb53 100644
--- a/indra/newview/llmachineid.cpp
+++ b/indra/newview/llmachineid.cpp
@@ -350,7 +350,7 @@ bool LLWMIMethods::getGenericSerialNumber(const BSTR &select, const LPCWSTR &var
 bool getSerialNumber(unsigned char *unique_id, size_t len)
 {
     CFStringRef serial_cf_str = NULL;
-    io_service_t platformExpert = IOServiceGetMatchingService(kIOMasterPortDefault,
+    io_service_t platformExpert = IOServiceGetMatchingService(kIOMainPortDefault,
                                                                  IOServiceMatching("IOPlatformExpertDevice"));
     if (platformExpert)
     {