--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -4416,33 +4416,33 @@ pref("webgl.restore-context-when-visible
 pref("webgl.max-warnings-per-context", 32);
 pref("webgl.enable-draft-extensions", false);
 pref("webgl.enable-privileged-extensions", false);
 pref("webgl.bypass-shader-validation", false);
 pref("webgl.disable-fail-if-major-performance-caveat", false);
 pref("webgl.disable-DOM-blit-uploads", false);
 pref("webgl.webgl2-compat-mode", false);
 
-pref("webgl.enable-webgl2", true);
+pref("webgl.enable-webgl2", false);
 
 #ifdef RELEASE_BUILD
 // Keep this disabled on Release and Beta for now. (see bug 1171228)
 pref("webgl.enable-debug-renderer-info", false);
 #else
 pref("webgl.enable-debug-renderer-info", true);
 #endif
 
 pref("webgl.renderer-string-override", "");
 pref("webgl.vendor-string-override", "");
 
 #ifdef XP_WIN
 pref("webgl.angle.try-d3d11", true);
 pref("webgl.angle.force-d3d11", false);
 pref("webgl.angle.force-warp", false);
-pref("webgl.dxgl.enabled", true);
+pref("webgl.dxgl.enabled", false);
 pref("webgl.dxgl.needs-finish", false);
 #endif
 
 pref("gfx.offscreencanvas.enabled", false);
 
 #ifdef MOZ_WIDGET_GONK
 pref("gfx.gralloc.fence-with-readpixels", false);
 #endif