--- a/layout/generic/nsTextFrame.cpp
+++ b/layout/generic/nsTextFrame.cpp
@@ -7257,16 +7257,20 @@ DrawTextRun(const gfxTextRun* aTextRun,
     if (NS_GET_A(aParams.textColor) != 0 || textDrawer) {
       aParams.context->SetColor(Color::FromABGR(aParams.textColor));
     } else {
       params.drawMode = DrawMode::GLYPH_STROKE;
     }
 
     if ((NS_GET_A(aParams.textStrokeColor) != 0 || textDrawer) &&
         aParams.textStrokeWidth != 0.0f) {
+      if (textDrawer) {
+        textDrawer->FoundUnsupportedFeature();
+        return;
+      }
       StrokeOptions strokeOpts;
       params.drawMode |= DrawMode::GLYPH_STROKE;
       params.textStrokeColor = aParams.textStrokeColor;
       strokeOpts.mLineWidth = aParams.textStrokeWidth;
       params.strokeOpts = &strokeOpts;
       aTextRun->Draw(aRange, aTextBaselinePt, params);
     } else {
       aTextRun->Draw(aRange, aTextBaselinePt, params);