diff --git a/src/osgText/shaders/osgText_Text_frag.cpp b/src/osgText/shaders/osgText_Text_frag.cpp
index 74af76369e3..94938741c85 100644
--- a/src/osgText/shaders/osgText_Text_frag.cpp
+++ b/src/osgText/shaders/osgText_Text_frag.cpp
@@ -38,6 +38,7 @@ char osgText_Text_frag[] = "$OSG_GLSL_VERSION\n"
                            "            #define TEXTURELOD texture2DLod\n"
                            "        #endif\n"
                            "    #else\n"
+                           "        #extension GL_ARB_shader_texture_lod : enable\n"
                            "        #define TEXTURELOD texture2DLod\n"
                            "    #endif\n"
                            "#endif\n"