diff --git a/image/test/reftest/downscaling/downscale-1-bigimage.png b/image/test/reftest/downscaling/downscale-1-bigimage.png
new file mode 100644
index 000000000000..5e018590c375
Binary files /dev/null and b/image/test/reftest/downscaling/downscale-1-bigimage.png differ
diff --git a/image/test/reftest/downscaling/downscale-1-ref.html b/image/test/reftest/downscaling/downscale-1-ref.html
new file mode 100644
index 000000000000..63ec56ef7ce3
--- /dev/null
+++ b/image/test/reftest/downscaling/downscale-1-ref.html
@@ -0,0 +1,8 @@
+<!DOCTYPE html>
+<!-- Any copyright is dedicated to the Public Domain.
+   - http://creativecommons.org/publicdomain/zero/1.0/ -->
+<html>
+<body>
+  <img src="downscale-1-smallimage.png">
+</body>
+</html>
diff --git a/image/test/reftest/downscaling/downscale-1-smallimage.png b/image/test/reftest/downscaling/downscale-1-smallimage.png
new file mode 100644
index 000000000000..588e6b78df68
Binary files /dev/null and b/image/test/reftest/downscaling/downscale-1-smallimage.png differ
diff --git a/image/test/reftest/downscaling/downscale-1.html b/image/test/reftest/downscaling/downscale-1.html
new file mode 100644
index 000000000000..a9629ef85530
--- /dev/null
+++ b/image/test/reftest/downscaling/downscale-1.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<!-- Any copyright is dedicated to the Public Domain.
+   - http://creativecommons.org/publicdomain/zero/1.0/ -->
+<html class="reftest-wait">
+<head>
+  <script>
+    function snapshot() {
+      document.documentElement.removeAttribute('class');
+    }
+  </script>
+</head>
+<!-- NOTE: Using setTimeout to wait for high-quality downscaled version of
+     image to be ready, because there's nothing better we can do. If we fix
+     Bug 1006883, we can do away with this setTimeout.
+
+     For now, the setTimeout is just here to increase the likelihood that we
+     actually test the high-quality downscaled version of the image. If the
+     setTimeout happens to fire before the high-quality downscaled rendering is
+     ready, then this the test will pass without testing what it's trying to
+     test, which is fine as long as that's rare.  -->
+<body onload="setTimeout(snapshot, 50)">
+  <img src="downscale-1-bigimage.png" style="height: 20px; width: 20px">
+</body>
+</html>
diff --git a/image/test/reftest/downscaling/reftest.list b/image/test/reftest/downscaling/reftest.list
new file mode 100644
index 000000000000..53f5988b0a21
--- /dev/null
+++ b/image/test/reftest/downscaling/reftest.list
@@ -0,0 +1,28 @@
+# Reftests for downscaling
+#
+# Downscaling can be a lossy process, so a bit of mismatch is acceptable here,
+# as long as it's barely noticable visually. When necessary, this can be
+# explicitly allowed via 'fuzzy'/'fuzzy-if' annotations.
+#
+# IMPORTANT: For robustness, each test should be listed *twice* in this
+# manifest -- once with the high quality downscaling pref disabled, and once
+# with this pref enabled. The pref is set via "default-preferences", so
+# simply appending a new test to the lists below each of those lines should be
+# sufficient.
+#
+# Also note that Mac OS X has its own system-level downscaling algorithm, so
+# tests here may need Mac-specific "fuzzy-if(cocoaWidget,...)" annotations.
+
+# RUN TESTS WITH HIGH QUALITY DOWNSCALING DISABLED:
+# =================================================
+default-preferences pref(image.high_quality_downscaling.enabled,false)
+
+fuzzy-if(cocoaWidget,106,31) == downscale-1.html downscale-1-ref.html
+
+
+# RUN TESTS WITH HIGH QUALITY DOWNSCALING ENABLED:
+# ================================================
+# High-quality downscaling enabled:
+default-preferences pref(image.high_quality_downscaling.enabled,true)
+
+fuzzy(31,127) == downscale-1.html downscale-1-ref.html
diff --git a/image/test/reftest/reftest.list b/image/test/reftest/reftest.list
index c5616cc40c3c..4eb2fc34ef6f 100644
--- a/image/test/reftest/reftest.list
+++ b/image/test/reftest/reftest.list
@@ -43,5 +43,8 @@ include generic/reftest.list
 # Color management test
 include color-management/reftest.list
 
+# Downscaling tests
+include downscaling/reftest.list
+
 # Lossless encoders
 skip-if(Android||B2G) include encoders-lossless/reftest.list # bug 783621
