diff --git a/Library/Homebrew/cask/cask.rb b/Library/Homebrew/cask/cask.rb
index 04f68cda0c..17918ea00f 100644
--- a/Library/Homebrew/cask/cask.rb
+++ b/Library/Homebrew/cask/cask.rb
@@ -23,9 +23,6 @@ module Cask
     HOMEBREW_PREFIX_PLACEHOLDER = "$HOMEBREW_PREFIX"
     APPDIR_PLACEHOLDER = "$APPDIR"
 
-    # TODO: can be removed when API JSON is regenerated with HOMEBREW_PREFIX_PLACEHOLDER.
-    HOMEBREW_OLD_PREFIX_PLACEHOLDER = "$(brew --prefix)"
-
     attr_reader :token, :sourcefile_path, :source, :config, :default_config, :loader
     attr_accessor :download, :allow_reassignment
 
diff --git a/Library/Homebrew/cask/cask_loader.rb b/Library/Homebrew/cask/cask_loader.rb
index 0fa41924df..44f0a64191 100644
--- a/Library/Homebrew/cask/cask_loader.rb
+++ b/Library/Homebrew/cask/cask_loader.rb
@@ -326,13 +326,10 @@ module Cask
       end
 
       def from_h_string_gsubs(string, appdir)
-        # TODO: HOMEBREW_OLD_PREFIX_PLACEHOLDER can be removed when API JSON is
-        #       regenerated with HOMEBREW_PREFIX_PLACEHOLDER.
         string.to_s
               .gsub(Cask::HOME_PLACEHOLDER, Dir.home)
               .gsub(Cask::HOMEBREW_PREFIX_PLACEHOLDER, HOMEBREW_PREFIX)
               .gsub(Cask::APPDIR_PLACEHOLDER, appdir)
-              .gsub(Cask::HOMEBREW_OLD_PREFIX_PLACEHOLDER, HOMEBREW_PREFIX)
       end
 
       def from_h_array_gsubs(array, appdir)