diff --git a/src/osgPlugins/dae/daeRMaterials.cpp b/src/osgPlugins/dae/daeRMaterials.cpp
index c46c98e68..d3195ab61 100644
--- a/src/osgPlugins/dae/daeRMaterials.cpp
+++ b/src/osgPlugins/dae/daeRMaterials.cpp
@@ -618,7 +618,7 @@ bool daeReader::processColorOrTextureType(const osg::StateSet* ss,
         else if (cot->getParam() != NULL)
         {
             domFloat4 f4;
-            if (GetFloat4Param(cot->getParam()->getRef(), f4))
+            if (cot->getParam()->getRef() != 0 && GetFloat4Param(cot->getParam()->getRef(), f4))
             {
                 mat->setAmbient( osg::Material::FRONT_AND_BACK, osg::Vec4( f4[0], f4[1], f4[2], f4[3] ) );
                 retVal = true;