--- a/dom/canvas/WebGLExtensionDepthTexture.cpp
+++ b/dom/canvas/WebGLExtensionDepthTexture.cpp
@@ -15,16 +15,17 @@ WebGLExtensionDepthTexture::WebGLExtensi
     : WebGLExtensionBase(webgl)
 {
     auto& fua = webgl->mFormatUsage;
 
     const auto fnAdd = [&fua](webgl::EffectiveFormat effFormat, GLenum unpackFormat,
                               GLenum unpackType)
     {
         auto usage = fua->EditUsage(effFormat);
+        usage->isFilterable = true;
         usage->SetRenderable();
 
         const webgl::PackingInfo pi = {unpackFormat, unpackType};
         const webgl::DriverUnpackInfo dui = {unpackFormat, unpackFormat, unpackType};
         fua->AddTexUnpack(usage, pi, dui);
 
         fua->AllowUnsizedTexFormat(pi, usage);
     };