diff --git a/include/osgDB/ReadFile b/include/osgDB/ReadFile
index c1a85583a..4d0670bb0 100644
--- a/include/osgDB/ReadFile
+++ b/include/osgDB/ReadFile
@@ -197,7 +197,7 @@ inline osg::ref_ptr<osg::Shader> readRefShaderFile(osg::Shader::Type type, const
   * The osgDB::Registry is used to load the appropriate ReaderWriter plugin
   * for the filename extension, and this plugin then handles the request
   * to read the specified file.*/
-osg::ref_ptr<osg::Shader> readRefShaderFileWithFallback(osg::Shader::Type type, const std::string& filename, const Options* options, const char* fallback);
+extern OSGDB_EXPORT osg::ref_ptr<osg::Shader> readRefShaderFileWithFallback(osg::Shader::Type type, const std::string& filename, const Options* options, const char* fallback);
 
 /** Read an osg::Shader from file and set to specified shader type, if a shader isn't loaded fallback to specific shader source.
   * The osgDB::Registry is used to load the appropriate ReaderWriter plugin