diff --git a/Rakefile b/Rakefile
index a6798fa0..5b2a66f5 100644
--- a/Rakefile
+++ b/Rakefile
@@ -40,7 +40,7 @@ task "snap_diff:clean" do
   patterns = ["**/*.diff.png", "**/*.base.diff.png", "**/*.heatmap.diff.png",
     "**/*.diff.webp", "**/*.base.diff.webp", "**/*.heatmap.diff.webp",
     "**/snap_diff_report.html"]
-  removed = patterns.flat_map { |p| Dir.glob("tmp/#{p}") + Dir.glob("doc/screenshots/#{p}") }
+  removed = patterns.flat_map { |p| Dir.glob("tmp/#{p}") + Dir.glob("doc/screenshots/#{p}") }.uniq
   removed.each { |f| FileUtils.rm_f(f) }
   puts "Removed #{removed.size} diff artifacts"
 end