diff --git a/content/canvas/test/webgl/non-conf-tests/mochitest.ini b/content/canvas/test/webgl/non-conf-tests/mochitest.ini
index d7eca9927af..b5dc7b94fb0 100644
--- a/content/canvas/test/webgl/non-conf-tests/mochitest.ini
+++ b/content/canvas/test/webgl/non-conf-tests/mochitest.ini
@@ -4,6 +4,7 @@ support-files =
   webgl-util.js
 
 [test_depth_readpixels.html]
+[test_fb_param.html]
 [test_highp_fs.html]
 [test_no_arr_points.html]
 [test_privileged_exts.html]
diff --git a/content/canvas/test/webgl/non-conf-tests/test_fb_param.html b/content/canvas/test/webgl/non-conf-tests/test_fb_param.html
new file mode 100644
index 00000000000..00fc70cd236
--- /dev/null
+++ b/content/canvas/test/webgl/non-conf-tests/test_fb_param.html
@@ -0,0 +1,55 @@
+<!DOCTYPE HTML>
+<title>WebGL test: bug 958491</title>
+<script src="/MochiKit/MochiKit.js"></script>
+<script src="/tests/SimpleTest/SimpleTest.js"></script>
+<link rel="stylesheet" href="/tests/SimpleTest/test.css">
+<script src="driver-info.js"></script>
+<script src="webgl-util.js"></script>
+<body>
+<canvas id="c"></canvas>
+<script>
+
+// Give ourselves a scope to return early from:
+(function() {
+  var gl = WebGLUtil.getWebGL('c');
+  if (!gl) {
+    todo(false, 'WebGL is unavailable.');
+    return;
+  }
+
+  // Catch actual WebGLUtil errors, not GL errors.
+  function errorFunc(str) {
+    ok(false, 'Error: ' + str);
+  }
+  WebGLUtil.setErrorFunc(errorFunc);
+
+  function checkGLError(func, info, reference) {
+    var error = gl.getError();
+    var prefix = info ? ('[' + info + '] ') : '';
+    var text = 'gl.getError should be 0x' + reference.toString(16) +
+               ', was 0x' + error.toString(16) + '.';
+    func(error == reference, prefix + text);
+  }
+
+  // Begin test:
+  var rb = gl.createRenderbuffer();
+  gl.bindRenderbuffer(gl.RENDERBUFFER, rb);
+  gl.renderbufferStorage(gl.RENDERBUFFER, gl.RGBA4, 4, 4);
+
+  var fb = gl.createFramebuffer();
+  gl.bindFramebuffer(gl.FRAMEBUFFER, fb);
+  gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0,
+                             gl.RENDERBUFFER, rb);
+
+  checkGLError(ok, 'before bad param query', 0);
+
+  var GL_FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING = 0x8210;
+  var result = gl.getFramebufferAttachmentParameter(gl.FRAMEBUFFER,
+                                                    gl.COLOR_ATTACHMENT0,
+                                                    GL_FRAMEBUFFER_ATTACHMENT_COLOR_ENCODING);
+
+  checkGLError(ok, 'after bad param query', gl.INVALID_ENUM);
+})();
+
+</script>
+
