diff --git a/src/osgPlugins/osg/StateSet.cpp b/src/osgPlugins/osg/StateSet.cpp
index 0dfd8a3b5..8ac5005a0 100644
--- a/src/osgPlugins/osg/StateSet.cpp
+++ b/src/osgPlugins/osg/StateSet.cpp
@@ -7,6 +7,9 @@
 #include <osgDB/Input>
 #include <osgDB/Output>
 
+#include <OpenThreads/Mutex>
+#include <OpenThreads/ScopedLock>
+
 #include <set>
 #include <string.h>
 
@@ -65,6 +68,11 @@ void initGLNames()
 {
     static bool first_time = true;
     if (!first_time) return;
+
+    static OpenThreads::Mutex s_initGLNames;
+    OpenThreads::ScopedLock<OpenThreads::Mutex> lock(s_initGLNames);
+
+    if (!first_time) return;
     
     ADD_NAME("GL_ALPHA_TEST",GL_ALPHA_TEST)
     ADD_NAME("GL_BLEND",GL_BLEND)