diff --git a/include/osg/Shader b/include/osg/Shader
index eeb2ba94c..5da7159a0 100644
--- a/include/osg/Shader
+++ b/include/osg/Shader
@@ -90,7 +90,7 @@ class OSG_EXPORT Shader : public osg::Object
             VERTEX = GL_VERTEX_SHADER,
             TESSCONTROL = GL_TESS_CONTROL_SHADER,
             TESSEVALUATION = GL_TESS_EVALUATION_SHADER,
-            GEOMETRY = GL_GEOMETRY_SHADER_EXT,
+            GEOMETRY = GL_GEOMETRY_SHADER,
             FRAGMENT = GL_FRAGMENT_SHADER,
             COMPUTE = GL_COMPUTE_SHADER,
             UNDEFINED = -1