--- a/dom/canvas/WebGLFramebuffer.cpp
+++ b/dom/canvas/WebGLFramebuffer.cpp
@@ -1465,17 +1465,17 @@ WebGLFramebuffer::FramebufferTextureLaye
 }
 
 JS::Value
 WebGLFramebuffer::GetAttachmentParameter(const char* funcName, JSContext* cx,
                                          GLenum target, GLenum attachEnum, GLenum pname,
                                          ErrorResult* const out_error)
 {
     const auto maybeAttach = GetAttachPoint(attachEnum);
-    if (!maybeAttach) {
+    if (!maybeAttach || attachEnum == LOCAL_GL_NONE) {
         mContext->ErrorInvalidEnum("%s: Can only query COLOR_ATTACHMENTi,"
                                    " DEPTH_ATTACHMENT, DEPTH_STENCIL_ATTACHMENT, or"
                                    " STENCIL_ATTACHMENT for a framebuffer.",
                                    funcName);
         return JS::NullValue();
     }
     auto attach = maybeAttach.value();