diff --git a/image/ClippedImage.cpp b/image/ClippedImage.cpp
index cdd2c569fb74..7ee260b4e0bd 100644
--- a/image/ClippedImage.cpp
+++ b/image/ClippedImage.cpp
@@ -196,11 +196,12 @@ ClippedImage::GetHeight(int32_t* aHeight) {
 }
 
 NS_IMETHODIMP
-ClippedImage::GetIntrinsicSize(nsSize* aSize) {
+ClippedImage::GetIntrinsicSizeInAppUnits(nsSize* aSize) {
   if (!ShouldClip()) {
-    return InnerImage()->GetIntrinsicSize(aSize);
+    return InnerImage()->GetIntrinsicSizeInAppUnits(aSize);
   }
 
+  // XXXdholbert This probably needs to be scaled; see bug 1965106.
   *aSize = nsSize(mClip.Width(), mClip.Height());
   return NS_OK;
 }
diff --git a/image/ClippedImage.h b/image/ClippedImage.h
index bb7a307b143f..91685f08e13b 100644
--- a/image/ClippedImage.h
+++ b/image/ClippedImage.h
@@ -35,7 +35,7 @@ class ClippedImage : public ImageWrapper {
 
   NS_IMETHOD GetWidth(int32_t* aWidth) override;
   NS_IMETHOD GetHeight(int32_t* aHeight) override;
-  NS_IMETHOD GetIntrinsicSize(nsSize* aSize) override;
+  NS_IMETHOD GetIntrinsicSizeInAppUnits(nsSize* aSize) override;
   AspectRatio GetIntrinsicRatio() override;
   NS_IMETHOD_(already_AddRefed<SourceSurface>)
   GetFrame(uint32_t aWhichFrame, uint32_t aFlags) override;
diff --git a/image/DynamicImage.cpp b/image/DynamicImage.cpp
index d93389a58e9f..4cfaba373916 100644
--- a/image/DynamicImage.cpp
+++ b/image/DynamicImage.cpp
@@ -98,7 +98,8 @@ nsresult DynamicImage::GetNativeSizes(nsTArray<IntSize>&) {
 size_t DynamicImage::GetNativeSizesLength() { return 0; }
 
 NS_IMETHODIMP
-DynamicImage::GetIntrinsicSize(nsSize* aSize) {
+DynamicImage::GetIntrinsicSizeInAppUnits(nsSize* aSize) {
+  // XXXdholbert This probably needs to be scaled; see bug 1965106.
   IntSize intSize(mDrawable->Size());
   *aSize = nsSize(intSize.width, intSize.height);
   return NS_OK;
diff --git a/image/ImageWrapper.cpp b/image/ImageWrapper.cpp
index ecfae461dc3a..5b6909f54e14 100644
--- a/image/ImageWrapper.cpp
+++ b/image/ImageWrapper.cpp
@@ -115,8 +115,8 @@ size_t ImageWrapper::GetNativeSizesLength() {
 }
 
 NS_IMETHODIMP
-ImageWrapper::GetIntrinsicSize(nsSize* aSize) {
-  return mInnerImage->GetIntrinsicSize(aSize);
+ImageWrapper::GetIntrinsicSizeInAppUnits(nsSize* aSize) {
+  return mInnerImage->GetIntrinsicSizeInAppUnits(aSize);
 }
 
 AspectRatio ImageWrapper::GetIntrinsicRatio() {
diff --git a/image/OrientedImage.cpp b/image/OrientedImage.cpp
index 47a293b71f61..321c4f2ae7ee 100644
--- a/image/OrientedImage.cpp
+++ b/image/OrientedImage.cpp
@@ -56,8 +56,8 @@ nsresult OrientedImage::GetNativeSizes(nsTArray<IntSize>& aNativeSizes) {
 }
 
 NS_IMETHODIMP
-OrientedImage::GetIntrinsicSize(nsSize* aSize) {
-  nsresult rv = InnerImage()->GetIntrinsicSize(aSize);
+OrientedImage::GetIntrinsicSizeInAppUnits(nsSize* aSize) {
+  nsresult rv = InnerImage()->GetIntrinsicSizeInAppUnits(aSize);
 
   if (mOrientation.SwapsWidthAndHeight()) {
     swap(aSize->width, aSize->height);
diff --git a/image/OrientedImage.h b/image/OrientedImage.h
index f74902b57ad9..270957107330 100644
--- a/image/OrientedImage.h
+++ b/image/OrientedImage.h
@@ -30,7 +30,7 @@ class OrientedImage : public ImageWrapper {
   NS_IMETHOD GetWidth(int32_t* aWidth) override;
   NS_IMETHOD GetHeight(int32_t* aHeight) override;
   nsresult GetNativeSizes(nsTArray<gfx::IntSize>& aNativeSizes) override;
-  NS_IMETHOD GetIntrinsicSize(nsSize* aSize) override;
+  NS_IMETHOD GetIntrinsicSizeInAppUnits(nsSize* aSize) override;
   AspectRatio GetIntrinsicRatio() override;
   NS_IMETHOD_(already_AddRefed<SourceSurface>)
   GetFrame(uint32_t aWhichFrame, uint32_t aFlags) override;
diff --git a/image/RasterImage.cpp b/image/RasterImage.cpp
index eb0ebc9c5e98..04ecd06bcdae 100644
--- a/image/RasterImage.cpp
+++ b/image/RasterImage.cpp
@@ -245,7 +245,7 @@ size_t RasterImage::GetNativeSizesLength() {
 
 //******************************************************************************
 NS_IMETHODIMP
-RasterImage::GetIntrinsicSize(nsSize* aSize) {
+RasterImage::GetIntrinsicSizeInAppUnits(nsSize* aSize) {
   if (mError) {
     return NS_ERROR_FAILURE;
   }
diff --git a/image/VectorImage.cpp b/image/VectorImage.cpp
index 354a9be6eb76..fab57406bd91 100644
--- a/image/VectorImage.cpp
+++ b/image/VectorImage.cpp
@@ -499,7 +499,7 @@ VectorImage::GetHeight(int32_t* aHeight) {
 
 //******************************************************************************
 NS_IMETHODIMP
-VectorImage::GetIntrinsicSize(nsSize* aSize) {
+VectorImage::GetIntrinsicSizeInAppUnits(nsSize* aSize) {
   if (mError || !mIsFullyLoaded) {
     return NS_ERROR_FAILURE;
   }
diff --git a/image/imgIContainer.idl b/image/imgIContainer.idl
index 82396b80c7fa..43ff00771a91 100644
--- a/image/imgIContainer.idl
+++ b/image/imgIContainer.idl
@@ -102,8 +102,12 @@ interface imgIContainer : nsISupports
    * The intrinsic size of this image in appunits. If the image has no intrinsic
    * size in a dimension, -1 will be returned for that dimension. In the case of
    * any error, an exception will be thrown.
+   *
+   * XXXdholbert maybe this should use the actual IntrinsicSize type (defined
+   * in nsIFrame.h, specifically for replaced elements like images, also
+   * using nscoord units but with Maybe<> to represent sizes being missing)?
    */
-  [noscript] readonly attribute nsSize intrinsicSize;
+  [noscript] readonly attribute nsSize intrinsicSizeInAppUnits;
 
   /**
    * The (dimensionless) intrinsic ratio of this image. Might return a
diff --git a/layout/generic/nsImageFrame.cpp b/layout/generic/nsImageFrame.cpp
index a882040029ce..35517a28e9a5 100644
--- a/layout/generic/nsImageFrame.cpp
+++ b/layout/generic/nsImageFrame.cpp
@@ -852,7 +852,7 @@ IntrinsicSize nsImageFrame::ComputeIntrinsicSize(
   }
 
   nsSize size;
-  if (mImage && NS_SUCCEEDED(mImage->GetIntrinsicSize(&size))) {
+  if (mImage && NS_SUCCEEDED(mImage->GetIntrinsicSizeInAppUnits(&size))) {
     IntrinsicSize intrinsicSize;
     intrinsicSize.width = size.width == -1 ? Nothing() : Some(size.width);
     intrinsicSize.height = size.height == -1 ? Nothing() : Some(size.height);
@@ -1035,7 +1035,8 @@ bool nsImageFrame::GetSourceToDestTransform(nsTransform2D& aTransform) {
   // size (mIntrinsicSize), which can be scaled due to ResponsiveImageSelector,
   // see ScaleIntrinsicSizeForDensity.
   nsSize intrinsicSize;
-  if (!mImage || !NS_SUCCEEDED(mImage->GetIntrinsicSize(&intrinsicSize)) ||
+  if (!mImage ||
+      !NS_SUCCEEDED(mImage->GetIntrinsicSizeInAppUnits(&intrinsicSize)) ||
       intrinsicSize.IsEmpty()) {
     return false;
   }