diff --git a/lib/wraith/compare_images.rb b/lib/wraith/compare_images.rb
index dd78088e..fd89f5a1 100644
--- a/lib/wraith/compare_images.rb
+++ b/lib/wraith/compare_images.rb
@@ -31,7 +31,7 @@ def percentage(img_size, px_value, info)
   end
 
   def compare_task(base, compare, output, info)
-    cmdline = "compare -fuzz #{wraith.fuzz} -metric AE -highlight-color #{wraith.highlight_color} #{base} #{compare.shellescape} #{output}"
+    cmdline = "compare -fuzz #{wraith.fuzz} -metric AE -highlight-color #{wraith.highlight_color} #{base.shellescape} #{compare.shellescape} #{output.shellescape}"
     px_value = Open3.popen3(cmdline) { |_stdin, _stdout, stderr, _wait_thr| stderr.read }.to_f
     begin
       img_size = ImageSize.path(output).size.inject(:*)