diff --git a/src/osg/State.cpp b/src/osg/State.cpp
index 525eeb825..a87e96221 100644
--- a/src/osg/State.cpp
+++ b/src/osg/State.cpp
@@ -826,9 +826,13 @@ bool State::checkGLErrors(const char* str) const
     GLenum errorNo = glGetError();
     if (errorNo!=GL_NO_ERROR)
     {
-        osg::notify(WARN)<<"Warning: detected OpenGL error '"<<gluErrorString(errorNo);
+        const char* error = (char*)gluErrorString(errorNo);
+        if (error) osg::notify(WARN)<<"Warning: detected OpenGL error '" << error;
+        else       osg::notify(WARN)<<"Warning: detected OpenGL error '" << errorNo;
+
         if (str) osg::notify(WARN)<<"' at "<<str<< std::endl;
-        else osg::notify(WARN)<<"' in osg::State."<< std::endl;
+        else     osg::notify(WARN)<<"' in osg::State."<< std::endl;
+
         return true;
     }
     return false;
@@ -839,7 +843,10 @@ bool State::checkGLErrors(StateAttribute::GLMode mode) const
     GLenum errorNo = glGetError();
     if (errorNo!=GL_NO_ERROR)
     {
-        osg::notify(WARN)<<"Warning: detected OpenGL error '"<<gluErrorString(errorNo)<<"' after applying GLMode 0x"<<hex<<mode<<dec<< std::endl;
+        const char* error = (char*)gluErrorString(errorNo);
+        if (error) osg::notify(WARN)<<"Warning: detected OpenGL error '"<< error <<"' after applying GLMode 0x"<<hex<<mode<<dec<< std::endl;
+        else       osg::notify(WARN)<<"Warning: detected OpenGL error '"<< errorNo <<"' after applying GLMode 0x"<<hex<<mode<<dec<< std::endl;
+
         return true;
     }
     return false;
@@ -850,10 +857,13 @@ bool State::checkGLErrors(const StateAttribute* attribute) const
     GLenum errorNo = glGetError();
     if (errorNo!=GL_NO_ERROR)
     {
-        osg::notify(WARN)<<"Warning: detected OpenGL error '"<<gluErrorString(errorNo)<<"' after applying attribute "<<attribute->className()<<" "<<attribute<< std::endl;
-        //attribute->apply(*this);
+        const char* error = (char*)gluErrorString(errorNo);
+        if (error) osg::notify(WARN)<<"Warning: detected OpenGL error '"<< error <<"' after applying attribute "<<attribute->className()<<" "<<attribute<< std::endl;
+        else       osg::notify(WARN)<<"Warning: detected OpenGL error '"<< errorNo <<"' after applying attribute "<<attribute->className()<<" "<<attribute<< std::endl;
+
         return true;
     }
     return false;
 }
 
+