diff --git a/test/Makefile.refs b/test/Makefile.refs
index 3a40b4721..b4bd33653 100644
--- a/test/Makefile.refs
+++ b/test/Makefile.refs
@@ -2698,9 +2698,10 @@ REFERENCE_IMAGES = \
 	reference/tiger.ref.png \
 	reference/tiger.traps.argb32.ref.png \
 	reference/tiger.traps.rgb24.ref.png \
+	reference/tighten-bounds.argb32.ref.png \
 	reference/tighten-bounds.base.argb32.ref.png \
 	reference/tighten-bounds.base.rgb24.ref.png \
-	reference/tighten-bounds.ref.png \
+	reference/tighten-bounds.rgb24.ref.png \
 	reference/tighten-bounds.traps.argb32.ref.png \
 	reference/tighten-bounds.traps.rgb24.ref.png \
 	reference/transforms.base.argb32.ref.png \
diff --git a/test/reference/tighten-bounds.argb32.ref.png b/test/reference/tighten-bounds.argb32.ref.png
new file mode 100644
index 000000000..3fbd8a41b
Binary files /dev/null and b/test/reference/tighten-bounds.argb32.ref.png differ
diff --git a/test/reference/tighten-bounds.ref.png b/test/reference/tighten-bounds.ref.png
deleted file mode 100644
index 82310822d..000000000
Binary files a/test/reference/tighten-bounds.ref.png and /dev/null differ
diff --git a/test/reference/tighten-bounds.rgb24.ref.png b/test/reference/tighten-bounds.rgb24.ref.png
new file mode 100644
index 000000000..5f0161f8f
Binary files /dev/null and b/test/reference/tighten-bounds.rgb24.ref.png differ