diff --git a/content/canvas/src/WebGLContextNotSupported.cpp b/content/canvas/src/WebGLContextNotSupported.cpp
index b3f9b2940b9e..9147dc9dfe73 100644
--- a/content/canvas/src/WebGLContextNotSupported.cpp
+++ b/content/canvas/src/WebGLContextNotSupported.cpp
@@ -52,3 +52,4 @@ DOMCI_DATA(WebGLFramebuffer, void)
 DOMCI_DATA(WebGLRenderbuffer, void)
 DOMCI_DATA(WebGLUniformLocation, void)
 DOMCI_DATA(WebGLActiveInfo, void)
+DOMCI_DATA(WebGLExtension, void)