diff --git a/src/library_glfw.js b/src/library_glfw.js
index ef148b6eb658f..e12ec756d3520 100644
--- a/src/library_glfw.js
+++ b/src/library_glfw.js
@@ -1610,7 +1610,7 @@ var LibraryGLFW = {
     return prevcbfun;
   },
 
-  glfwSetWindowContentScaleCallback_sig: 'iii',
+  glfwSetWindowContentScaleCallback__sig: 'iii',
   glfwSetWindowContentScaleCallback: function(winid, cbfun) {
     var win = GLFW.WindowFromId(winid);
     if (!win) return null;