diff --git a/src/gfx/process.cpp b/src/gfx/process.cpp
index c679fc17..0230f9ec 100644
--- a/src/gfx/process.cpp
+++ b/src/gfx/process.cpp
@@ -822,7 +822,7 @@ static UniqueTiles dedupTiles(
 			attr.bank = 0;
 			attr.tileID = 0;
 		} else {
-			auto [tileID, matchType] = tiles.addTile({tile, palettes[mappings[attr.colorSetID]]});
+			auto [tileID, matchType] = tiles.addTile({tile, palettes[attr.getPalID(mappings)]});
 
 			if (inputWithoutOutput && matchType == TileData::NOPE) {
 				error(
diff --git a/test/gfx/dedup_transparent.flags b/test/gfx/dedup_transparent.flags
new file mode 100644
index 00000000..4bca84d6
--- /dev/null
+++ b/test/gfx/dedup_transparent.flags
@@ -0,0 +1 @@
+-m
diff --git a/test/gfx/dedup_transparent.out.2bpp b/test/gfx/dedup_transparent.out.2bpp
new file mode 100644
index 00000000..d498b688
Binary files /dev/null and b/test/gfx/dedup_transparent.out.2bpp differ
diff --git a/test/gfx/dedup_transparent.out.attrmap b/test/gfx/dedup_transparent.out.attrmap
new file mode 100644
index 00000000..3ed7cece
Binary files /dev/null and b/test/gfx/dedup_transparent.out.attrmap differ
diff --git a/test/gfx/dedup_transparent.out.pal b/test/gfx/dedup_transparent.out.pal
new file mode 100644
index 00000000..6cd5231c
Binary files /dev/null and b/test/gfx/dedup_transparent.out.pal differ
diff --git a/test/gfx/dedup_transparent.out.tilemap b/test/gfx/dedup_transparent.out.tilemap
new file mode 100644
index 00000000..a9ababdd
Binary files /dev/null and b/test/gfx/dedup_transparent.out.tilemap differ
diff --git a/test/gfx/dedup_transparent.png b/test/gfx/dedup_transparent.png
new file mode 100644
index 00000000..fb4e0776
Binary files /dev/null and b/test/gfx/dedup_transparent.png differ