--- a/dom/canvas/WebGLContextState.cpp
+++ b/dom/canvas/WebGLContextState.cpp
@@ -181,16 +181,20 @@ WebGLContext::GetParameter(JSContext* cx
         switch (pname) {
             case LOCAL_GL_MAX_SAMPLES:
             case LOCAL_GL_MAX_UNIFORM_BLOCK_SIZE:
             case LOCAL_GL_MAX_VERTEX_UNIFORM_COMPONENTS: {
                 GLint val;
                 gl->fGetIntegerv(pname, &val);
                 return JS::NumberValue(uint32_t(val));
             }
+
+            case LOCAL_GL_TEXTURE_BINDING_3D: {
+                return WebGLObjectAsJSValue(cx, mBound3DTextures[mActiveTexture].get(), rv);
+            }
         }
     }
 
     switch (pname) {
         //
         // String params
         //
         case LOCAL_GL_VENDOR: