diff --git a/dom/canvas/test/webgl-conf/checkout/js/webgl-test-utils.js b/dom/canvas/test/webgl-conf/checkout/js/webgl-test-utils.js
index 739b3c9473a7..311b164b065e 100644
--- a/dom/canvas/test/webgl-conf/checkout/js/webgl-test-utils.js
+++ b/dom/canvas/test/webgl-conf/checkout/js/webgl-test-utils.js
@@ -2966,6 +2966,7 @@ var startPlayingAndWaitForVideo = function(video, callback) {
 
   requestAnimFrame.call(window, timeWatcher);
   video.loop = true;
+  video.muted = true;
   video.play();
 };
 
diff --git a/dom/canvas/test/webgl-conf/generated-mochitest.ini b/dom/canvas/test/webgl-conf/generated-mochitest.ini
index d0865054ac0c..5f5d5de76dec 100644
--- a/dom/canvas/test/webgl-conf/generated-mochitest.ini
+++ b/dom/canvas/test/webgl-conf/generated-mochitest.ini
@@ -5096,7 +5096,6 @@ subsuite = webgl2-ext
 subsuite = webgl2-ext
 [generated/test_2_conformance2__glsl3__array-initialize-with-same-name-array.html]
 subsuite = webgl2-ext
-fail-if = (os == 'win')
 [generated/test_2_conformance2__glsl3__array-length-side-effects.html]
 subsuite = webgl2-ext
 [generated/test_2_conformance2__glsl3__attrib-location-length-limits.html]
@@ -7363,6 +7362,7 @@ subsuite = webgl2-core
 [generated/test_2_conformance2__transform_feedback__same-buffer-two-binding-points.html]
 subsuite = webgl2-core
 fail-if = 1
+skip-if = (os == 'win')
 [generated/test_2_conformance2__transform_feedback__simultaneous_binding.html]
 subsuite = webgl2-core
 fail-if = 1
diff --git a/dom/canvas/test/webgl-conf/mochitest-errata.ini b/dom/canvas/test/webgl-conf/mochitest-errata.ini
index 1a565d98fa79..16d04e5cbd71 100644
--- a/dom/canvas/test/webgl-conf/mochitest-errata.ini
+++ b/dom/canvas/test/webgl-conf/mochitest-errata.ini
@@ -155,6 +155,8 @@ fail-if = 1
 fail-if = 1
 [generated/test_2_conformance2__transform_feedback__same-buffer-two-binding-points.html]
 fail-if = 1
+# ABORT_ON_ERROR from ANGLE
+skip-if = (os == 'win')
 [generated/test_2_conformance2__transform_feedback__simultaneous_binding.html]
 fail-if = 1
 [generated/test_conformance__extensions__webgl-draw-buffers-feedback-loop.html]
@@ -1079,8 +1081,6 @@ skip-if = (os == 'win')
 skip-if = (os == 'win')
 [generated/test_conformance__rendering__preservedrawingbuffer-leak.html]
 skip-if = (os == 'win')
-[generated/test_2_conformance2__glsl3__array-initialize-with-same-name-array.html]
-fail-if = (os == 'win')
 [generated/test_2_conformance__misc__webgl-specific-stencil-settings.html]
 # [gl:0D6DE000] mozilla::gl::GLContext::raw_fDrawArrays: Generated unexpected GL_INVALID_OPERATION error. (0x0502)
 # ERR: gl::ValidateDrawBase(2519): This ANGLE implementation does not support separate front/back stencil writemasks, reference values, or stencil mask values.
diff --git a/dom/canvas/test/webgl-mochitest/mochitest.ini b/dom/canvas/test/webgl-mochitest/mochitest.ini
index 38bc874f90fa..824c493b9bc4 100644
--- a/dom/canvas/test/webgl-mochitest/mochitest.ini
+++ b/dom/canvas/test/webgl-mochitest/mochitest.ini
@@ -29,7 +29,7 @@ fail-if = (os == 'android')
 [ensure-exts/test_EXT_shader_texture_lod.html]
 fail-if = (os == 'android')
 [ensure-exts/test_EXT_texture_compression_bptc.html]
-fail-if = (os == 'android') || (os == 'linux') || (os == 'mac') || (os == 'win')
+fail-if = (os == 'android') || (os == 'linux') || (os == 'mac')
 [ensure-exts/test_EXT_texture_compression_rgtc.html]
 fail-if = (os == 'android') || (os == 'win')
 [ensure-exts/test_EXT_texture_filter_anisotropic.html]