diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 5cb9d94e27..ab90329020 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -1165,6 +1165,8 @@ class Formula
     active_spec.fetch if fetch
     stage do |staging|
       staging.retain! if Homebrew.args.keep_tmp?
+
+      prepare_patches
       fetch_patches if fetch
 
       begin
@@ -2082,14 +2084,16 @@ class Formula
   end
 
   def fetch_patches
-    active_spec.add_legacy_patches(patches) if respond_to?(:patches)
-
-    patchlist.grep(DATAPatch) { |p| p.path = path }
     patchlist.select(&:external?).each(&:fetch)
   end
 
   private
 
+  def prepare_patches
+    active_spec.add_legacy_patches(patches) if respond_to?(:patches)
+    patchlist.grep(DATAPatch) { |p| p.path = path }
+  end
+
   # Returns the prefix for a given formula version number.
   # @private
   def versioned_prefix(v)
diff --git a/Library/Homebrew/resource.rb b/Library/Homebrew/resource.rb
index dec25c6de1..a02d197f0a 100644
--- a/Library/Homebrew/resource.rb
+++ b/Library/Homebrew/resource.rb
@@ -74,14 +74,18 @@ class Resource
   def stage(target = nil, &block)
     raise ArgumentError, "target directory or block is required" if target.blank? && block.blank?
 
+    prepare_patches
     fetch_patches(skip_downloaded: true)
     fetch unless downloaded?
 
     unpack(target, &block)
   end
 
-  def fetch_patches(skip_downloaded: false)
+  def prepare_patches
     patches.grep(DATAPatch) { |p| p.path = owner.owner.path }
+  end
+
+  def fetch_patches(skip_downloaded: false)
     patches.select!(&:external?)
     patches.reject!(&:downloaded?) if skip_downloaded
     patches.each(&:fetch)