--- a/layout/painting/nsCSSRendering.cpp
+++ b/layout/painting/nsCSSRendering.cpp
@@ -815,34 +815,38 @@ nsCSSRendering::PaintBorderWithStyleBord
     nsITheme *theme = aPresContext->GetTheme();
     if (theme &&
         theme->ThemeSupportsWidget(aPresContext, aForFrame,
                                    displayData->UsedAppearance())) {
       return DrawResult::SUCCESS; // Let the theme handle it.
     }
   }
 
-  if (aStyleBorder.IsBorderImageLoaded()) {
-    DrawResult result;
+  if (!aStyleBorder.mBorderImageSource.IsEmpty()) {
+    DrawResult result = DrawResult::SUCCESS;
 
     uint32_t irFlags = 0;
     if (aFlags & PaintBorderFlags::SYNC_DECODE_IMAGES) {
       irFlags |= nsImageRenderer::FLAG_SYNC_DECODE_IMAGES;
     }
 
+    // Creating the border image renderer will request a decode, and we rely on
+    // that happening.
     Maybe<nsCSSBorderImageRenderer> renderer =
       nsCSSBorderImageRenderer::CreateBorderImageRenderer(aPresContext, aForFrame, aBorderArea,
                                                           aStyleBorder, aDirtyRect, aSkipSides,
                                                           irFlags, &result);
-    if (!renderer) {
-      return result;
+    if (aStyleBorder.IsBorderImageLoaded()) {
+      if (!renderer) {
+        return result;
+      }
+
+      return renderer->DrawBorderImage(aPresContext, aRenderingContext,
+                                       aForFrame, aDirtyRect);
     }
-
-    return renderer->DrawBorderImage(aPresContext, aRenderingContext,
-                                     aForFrame, aDirtyRect);
   }
 
   DrawResult result = DrawResult::SUCCESS;
 
   // If we had a border-image, but it wasn't loaded, then we should return
   // DrawResult::NOT_READY; we'll want to try again if we do a paint with sync
   // decoding enabled.
   if (aStyleBorder.mBorderImageSource.GetType() != eStyleImageType_Null) {

--- a/layout/painting/nsCSSRenderingBorders.cpp
+++ b/layout/painting/nsCSSRenderingBorders.cpp
@@ -3580,18 +3580,16 @@ nsCSSBorderImageRenderer::CreateBorderIm
                                                     nsIFrame* aForFrame,
                                                     const nsRect& aBorderArea,
                                                     const nsStyleBorder& aStyleBorder,
                                                     const nsRect& aDirtyRect,
                                                     Sides aSkipSides,
                                                     uint32_t aFlags,
                                                     DrawResult* aDrawResult)
 {
-  NS_PRECONDITION(aStyleBorder.IsBorderImageLoaded(),
-                  "drawing border image that isn't successfully loaded");
   MOZ_ASSERT(aDrawResult);
 
   if (aDirtyRect.IsEmpty()) {
     *aDrawResult = DrawResult::SUCCESS;
     return Nothing();
   }
 
   nsImageRenderer imgRenderer(aForFrame, &aStyleBorder.mBorderImageSource, aFlags);