diff --git a/completions/bash/brew b/completions/bash/brew
index adc749389d..5480ad4172 100644
--- a/completions/bash/brew
+++ b/completions/bash/brew
@@ -1829,10 +1829,12 @@ _brew_readall() {
     -*)
       __brewcomp "
       --aliases
+      --arch
       --debug
       --eval-all
       --help
       --no-simulate
+      --os
       --quiet
       --syntax
       --verbose
diff --git a/completions/fish/brew.fish b/completions/fish/brew.fish
index 6dfe77bf30..f0cafd42b4 100644
--- a/completions/fish/brew.fish
+++ b/completions/fish/brew.fish
@@ -1236,10 +1236,12 @@ __fish_brew_complete_arg 'rbenv-sync' -l verbose -d 'Make some output more verbo
 
 __fish_brew_complete_cmd 'readall' 'Import all items from the specified tap, or from all installed taps if none is provided'
 __fish_brew_complete_arg 'readall' -l aliases -d 'Verify any alias symlinks in each tap'
+__fish_brew_complete_arg 'readall' -l arch -d 'Read using the given CPU architecture. (Pass `all` to simulate all architectures.)'
 __fish_brew_complete_arg 'readall' -l debug -d 'Display any debugging information'
 __fish_brew_complete_arg 'readall' -l eval-all -d 'Evaluate all available formulae and casks, whether installed or not. Implied if `HOMEBREW_EVAL_ALL` is set'
 __fish_brew_complete_arg 'readall' -l help -d 'Show this message'
 __fish_brew_complete_arg 'readall' -l no-simulate -d 'Don\'t simulate other system configurations when checking formulae and casks'
+__fish_brew_complete_arg 'readall' -l os -d 'Read using the given operating system. (Pass `all` to simulate all operating systems.)'
 __fish_brew_complete_arg 'readall' -l quiet -d 'Make some output more quiet'
 __fish_brew_complete_arg 'readall' -l syntax -d 'Syntax-check all of Homebrew\'s Ruby files (if no `tap` is passed)'
 __fish_brew_complete_arg 'readall' -l verbose -d 'Make some output more verbose'
diff --git a/completions/zsh/_brew b/completions/zsh/_brew
index 732508ff8e..94e026b954 100644
--- a/completions/zsh/_brew
+++ b/completions/zsh/_brew
@@ -1525,10 +1525,12 @@ _brew_rbenv_sync() {
 _brew_readall() {
   _arguments \
     '--aliases[Verify any alias symlinks in each tap]' \
+    '--arch[Read using the given CPU architecture. (Pass `all` to simulate all architectures.)]' \
     '--debug[Display any debugging information]' \
     '--eval-all[Evaluate all available formulae and casks, whether installed or not. Implied if `HOMEBREW_EVAL_ALL` is set]' \
     '--help[Show this message]' \
     '--no-simulate[Don'\''t simulate other system configurations when checking formulae and casks]' \
+    '--os[Read using the given operating system. (Pass `all` to simulate all operating systems.)]' \
     '--quiet[Make some output more quiet]' \
     '--syntax[Syntax-check all of Homebrew'\''s Ruby files (if no `tap` is passed)]' \
     '--verbose[Make some output more verbose]' \
diff --git a/docs/Manpage.md b/docs/Manpage.md
index a6a185492c..181a72c715 100644
--- a/docs/Manpage.md
+++ b/docs/Manpage.md
@@ -551,6 +551,10 @@ This can be useful for debugging issues across all items when making
 significant changes to `formula.rb`, testing the performance of loading
 all items or checking if any current formulae/casks have Ruby issues.
 
+* `--os`:
+  Read using the given operating system. (Pass `all` to simulate all operating systems.)
+* `--arch`:
+  Read using the given CPU architecture. (Pass `all` to simulate all architectures.)
 * `--aliases`:
   Verify any alias symlinks in each tap.
 * `--syntax`:
diff --git a/manpages/brew.1 b/manpages/brew.1
index 154e3ab416..52079b4404 100644
--- a/manpages/brew.1
+++ b/manpages/brew.1
@@ -759,6 +759,14 @@ Note that older version symlinks will also be created so e\.g\. Ruby 3\.2\.1 wil
 Import all items from the specified \fItap\fR, or from all installed taps if none is provided\. This can be useful for debugging issues across all items when making significant changes to \fBformula\.rb\fR, testing the performance of loading all items or checking if any current formulae/casks have Ruby issues\.
 .
 .TP
+\fB\-\-os\fR
+Read using the given operating system\. (Pass \fBall\fR to simulate all operating systems\.)
+.
+.TP
+\fB\-\-arch\fR
+Read using the given CPU architecture\. (Pass \fBall\fR to simulate all architectures\.)
+.
+.TP
 \fB\-\-aliases\fR
 Verify any alias symlinks in each tap\.
 .