diff --git a/app/models/optimized_image.rb b/app/models/optimized_image.rb
index 5f7f085addd..a2e247d67e9 100644
--- a/app/models/optimized_image.rb
+++ b/app/models/optimized_image.rb
@@ -215,7 +215,11 @@ class OptimizedImage < ActiveRecord::Base
   end
 
   def self.convert_with(instructions, to)
-    return false unless system(instructions.join(" "), '&> /dev/null')
+    begin
+      Discourse::Utils.execute_command(*instructions)
+    rescue
+      return false
+    end
 
     ImageOptim.new.optimize_image!(to)
     true