diff --git a/pkgs/development/compilers/factor-lang/mk-factor-application.nix b/pkgs/development/compilers/factor-lang/mk-factor-application.nix
index 0537f74ddda8..bbd039ba3615 100644
--- a/pkgs/development/compilers/factor-lang/mk-factor-application.nix
+++ b/pkgs/development/compilers/factor-lang/mk-factor-application.nix
@@ -33,10 +33,22 @@ in
     extraVocabs ? [ ],
     deployScriptText ? /* factor */ ''
       USING: command-line io io.backend io.pathnames kernel namespaces sequences
-      tools.deploy tools.deploy.config tools.deploy.backend vocabs.loader ;
+      tools.deploy tools.deploy.config tools.deploy.backend vocabs.loader
+      io.directories.unix ;
 
       IN: deploy-me
 
+      ! The Nix sandbox’s seccomp filter blocks chmod(2). Factor’s
+      ! copy-file calls set-file-permissions which chmod’s the target
+      ! to the source’s mode, 0o444. The blocked syscall returns
+      ! EACCES, crashing the deploys. The method override skips the
+      ! set-file-permissions call (Nix will manage its output
+      ! permissions).
+      !
+      ! Surfaced with Factor 0.101 which added icon PNG resources to
+      ! the definitions.icons vocab to copy-vocab-resources.
+      M: unix copy-file call-next-method ;
+
       : load-and-deploy ( path/vocab -- )
           normalize-path [
               parent-directory add-vocab-root