diff --git a/Library/Contributions/example-formula.rb b/Library/Contributions/example-formula.rb
index e48199f39a..fe96551f60 100644
--- a/Library/Contributions/example-formula.rb
+++ b/Library/Contributions/example-formula.rb
@@ -29,17 +29,17 @@ class ExampleFormula < Formula
   # version is seldom needed, because it's usually autodetected from the URL/tag.
   version "1.2-final"
 
-  # For integrity and security, we verify the hash (`openssl dgst -sha1 <FILE>`)
-  # You may also use sha256 if the software uses sha256 on their homepage. Do not use md5.
+  # For integrity and security, we verify the hash (`openssl dgst -sha256 <FILE>`)
+  # You should use SHA256. Never use md5.
   # Either generate the sha locally or leave it empty & `brew install` will tell you the expected.
-  sha1 "cafebabe78901234567890123456789012345678"
+  sha256 "2a2ba417eebaadcb4418ee7b12fe2998f26d6e6f7fda7983412ff66a741ab6f7"
 
   # Stable-only dependencies should be nested inside a `stable` block rather than
   # using a conditional. It is preferrable to also pull the URL and checksum into
   # the block if one is necessary.
   stable do
     url "https://example.com/foo-1.0.tar.gz"
-    sha1 "cafebabe78901234567890123456789012345678"
+    sha256 "2a2ba417eebaadcb4418ee7b12fe2998f26d6e6f7fda7983412ff66a741ab6f7"
 
     depends_on "libxml2"
     depends_on "libffi"
@@ -65,7 +65,7 @@ class ExampleFormula < Formula
   # Use this to specify a not-yet-released version of a software.
   devel do
     url "https://example.com/archive-2.0-beta.tar.gz"
-    sha1 "1234567890123456789012345678901234567890"
+    sha256 "2a2ba417eebaadcb4418ee7b12fe2998f26d6e6f7fda7983412ff66a741ab6f7"
 
     depends_on "cairo"
     depends_on "pixman"
@@ -97,9 +97,9 @@ class ExampleFormula < Formula
     prefix "/opt/homebrew" # Optional HOMEBREW_PREFIX in which the bottles were built.
     cellar "/opt/homebrew/Cellar" # Optional HOMEBREW_CELLAR in which the bottles were built.
     revision 1 # Making the old bottle outdated without bumping the version of the formula.
-    sha1 "d3d13fe6f42416765207503a946db01378131d7b" => :yosemite
-    sha1 "cdc48e79de2dee796bb4ba1ad987f6b35ce1c1ee" => :mavericks
-    sha1 "a19b544c8c645d7daad1d39a070a0eb86dfe9b9c" => :mountain_lion
+    sha256 "2a2ba417eebaadcb4418ee7b12fe2998f26d6e6f7fda7983412ff66a741ab6f7" => :yosemite
+    sha256 "2a2ba417eebaadcb4418ee7b12fe2998f26d6e6f7fda7983412ff66a741ab6f7" => :mavericks
+    sha256 "2a2ba417eebaadcb4418ee7b12fe2998f26d6e6f7fda7983412ff66a741ab6f7" => :mountain_lion
   end
 
   def pour_bottle?
@@ -204,7 +204,7 @@ class ExampleFormula < Formula
   # head block. This mechanism replaces ad-hoc "subformula" classes.
   resource "additional_files" do
     url "https://example.com/additional-stuff.tar.gz"
-    sha1 "deadbeef7890123456789012345678901234567890"
+    sha256 "c6bc3f48ce8e797854c4b865f6a8ff969867bbcaebd648ae6fd825683e59fef2"
   end
 
 
@@ -213,14 +213,14 @@ class ExampleFormula < Formula
   # External patches can be declared using resource-style blocks.
   patch do
     url "https://example.com/example_patch.diff"
-    sha1 "deadbeefdeadbeefdeadbeefdeadbeefdeadbeef"
+    sha256 "c6bc3f48ce8e797854c4b865f6a8ff969867bbcaebd648ae6fd825683e59fef2"
   end
 
   # A strip level of -p1 is assumed. It can be overridden using a symbol
   # argument:
   patch :p0 do
     url "https://example.com/example_patch.diff"
-    sha1 "deadbeefdeadbeefdeadbeefdeadbeefdeadbeef"
+    sha256 "c6bc3f48ce8e797854c4b865f6a8ff969867bbcaebd648ae6fd825683e59fef2"
   end
 
   # Patches can be declared in stable, devel, and head blocks. This form is
@@ -228,7 +228,7 @@ class ExampleFormula < Formula
   stable do
     patch do
       url "https://example.com/example_patch.diff"
-      sha1 "deadbeefdeadbeefdeadbeefdeadbeefdeadbeef"
+      sha256 "c6bc3f48ce8e797854c4b865f6a8ff969867bbcaebd648ae6fd825683e59fef2"
     end
   end
 
diff --git a/Library/Homebrew/cmd/audit.rb b/Library/Homebrew/cmd/audit.rb
index eefbf82866..2354cb3c27 100644
--- a/Library/Homebrew/cmd/audit.rb
+++ b/Library/Homebrew/cmd/audit.rb
@@ -846,9 +846,15 @@ class ResourceAuditor
 
     case checksum.hash_type
     when :md5
-      problem "MD5 checksums are deprecated, please use SHA1 or SHA256"
+      problem "MD5 checksums are deprecated, please use SHA256"
       return
-    when :sha1   then len = 40
+    when :sha1
+      if ARGV.include? "--strict"
+        problem "SHA1 checksums are deprecated, please use SHA256"
+        return
+      else
+        len = 40
+      end
     when :sha256 then len = 64
     end
 
diff --git a/Library/Homebrew/cmd/bottle.rb b/Library/Homebrew/cmd/bottle.rb
index dcbc0e2ce4..77b75ed821 100644
--- a/Library/Homebrew/cmd/bottle.rb
+++ b/Library/Homebrew/cmd/bottle.rb
@@ -202,7 +202,7 @@ module Homebrew
     bottle.prefix prefix
     bottle.cellar relocatable ? :any : cellar
     bottle.revision bottle_revision
-    bottle.sha1 bottle_path.sha1 => bottle_tag
+    bottle.sha256 bottle_path.sha256 => bottle_tag
 
     output = bottle_output bottle
 
diff --git a/Library/Homebrew/cmd/create.rb b/Library/Homebrew/cmd/create.rb
index 3f169be219..b9bc9cd136 100644
--- a/Library/Homebrew/cmd/create.rb
+++ b/Library/Homebrew/cmd/create.rb
@@ -73,7 +73,7 @@ module Homebrew
 end
 
 class FormulaCreator
-  attr_reader :url, :sha1
+  attr_reader :url, :sha256
   attr_accessor :name, :version, :path, :mode
 
   def url= url
@@ -112,7 +112,7 @@ class FormulaCreator
       r.url(url)
       r.version(version)
       r.owner = self
-      @sha1 = r.fetch.sha1 if r.download_strategy == CurlDownloadStrategy
+      @sha256 = r.fetch.sha256 if r.download_strategy == CurlDownloadStrategy
     end
 
     path.write ERB.new(template, nil, '>').result(binding)
@@ -129,7 +129,7 @@ class FormulaCreator
     <% unless version.nil? or version.detected_from_url? %>
       version "#{version}"
     <% end %>
-      sha1 "#{sha1}"
+      sha256 "#{sha256}"
 
     <% if mode == :cmake %>
       depends_on "cmake" => :build
diff --git a/Library/Homebrew/resource.rb b/Library/Homebrew/resource.rb
index 92c9fa91ba..4aa0e96404 100644
--- a/Library/Homebrew/resource.rb
+++ b/Library/Homebrew/resource.rb
@@ -122,7 +122,7 @@ class Resource
   rescue ChecksumMissingError
     opoo "Cannot verify integrity of #{fn.basename}"
     puts "A checksum was not provided for this resource"
-    puts "For your reference the SHA1 is: #{fn.sha1}"
+    puts "For your reference the SHA256 is: #{fn.sha256}"
   end
 
   Checksum::TYPES.each do |type|
diff --git a/Library/Homebrew/test/test_resource.rb b/Library/Homebrew/test/test_resource.rb
index 245bc17893..ac72836e26 100644
--- a/Library/Homebrew/test/test_resource.rb
+++ b/Library/Homebrew/test/test_resource.rb
@@ -113,7 +113,7 @@ class ResourceTests < Homebrew::TestCase
 
     fn.stubs(:file? => true)
     fn.expects(:verify_checksum).raises(ChecksumMissingError)
-    fn.expects(:sha1)
+    fn.expects(:sha256)
 
     shutup { @resource.verify_download_integrity(fn) }
   end
diff --git a/share/doc/homebrew/Bottles.md b/share/doc/homebrew/Bottles.md
index 8b484662cc..ea54b170c1 100644
--- a/share/doc/homebrew/Bottles.md
+++ b/share/doc/homebrew/Bottles.md
@@ -23,9 +23,9 @@ Bottles have a DSL to be used in formulae which is contained in the `bottle do .
 A simple (and typical) example:
 ```ruby
 bottle do
-  sha1 "23ef6a81af2f37166d7d7423b88f7716bf9b0629" => :yosemite
-  sha1 "fdc919d750012fbfeeec8b3f95d07000adc3c946" => :mavericks
-  sha1 "0d08b3ca611f47a25a922b2d942f157f1d6268c1" => :mountain_lion
+  sha256 "4921af80137af9cc3d38fd17c9120da882448a090b0a8a3a19af3199b415bfca" => :yosemite
+  sha256 "c71db15326ee9196cd98602e38d0b7fb2b818cdd48eede4ee8eb827d809e09ba" => :mavericks
+  sha256 "85cc828a96735bdafcf29eb6291ca91bac846579bcef7308536e0c875d6c81d7" => :mountain_lion
 end
 ```
 
@@ -36,9 +36,9 @@ bottle do
   prefix "/opt/homebrew"
   cellar "/opt/homebrew/Cellar"
   revision 4
-  sha1 "23ef6a81af2f37166d7d7423b88f7716bf9b0629" => :yosemite
-  sha1 "fdc919d750012fbfeeec8b3f95d07000adc3c946" => :mavericks
-  sha1 "0d08b3ca611f47a25a922b2d942f157f1d6268c1" => :mountain_lion
+  sha256 "4921af80137af9cc3d38fd17c9120da882448a090b0a8a3a19af3199b415bfca" => :yosemite
+  sha256 "c71db15326ee9196cd98602e38d0b7fb2b818cdd48eede4ee8eb827d809e09ba" => :mavericks
+  sha256 "85cc828a96735bdafcf29eb6291ca91bac846579bcef7308536e0c875d6c81d7" => :mountain_lion
 end
 ```
 
@@ -58,8 +58,8 @@ See description of `cellar`. When `cellar` is `:any` prefix should be omitted.
 Optionally contains the revision of the bottle.
 Sometimes bottles may need be updated without bumping the version of the formula e.g. a new patch was applied. In that case the revision will have a value of 1 or more.
 
-### `sha1`
-Contains the SHA-1 of bottle for a particular version of OS X.
+### `sha256`
+Contains the SHA-256 of bottle for a particular version of OS X.
 
 ## Formula DSL
 Additionally there is a method available in the formula DSL.
diff --git a/share/doc/homebrew/Brew-Test-Bot-For-Core-Contributors.md b/share/doc/homebrew/Brew-Test-Bot-For-Core-Contributors.md
index 54140b5d02..619fd09fda 100644
--- a/share/doc/homebrew/Brew-Test-Bot-For-Core-Contributors.md
+++ b/share/doc/homebrew/Brew-Test-Bot-For-Core-Contributors.md
@@ -19,7 +19,7 @@ To pull and bottle a pull request with `brew pull`:
 
 1. Ensure the job has already completed successfully.
 2. Run `brew pull --bottle 12345` where `12345` is the pull request number (or URL). If it complains about a missing URL with `BrewTestBot` in it then the bottles have not finished uploading yet; wait and try again later.
-3. Run `brew fetch --force-bottle $FORMULAE` to check the SHA-1 in the bottled formulae match the uploaded files.
+3. Run `brew fetch --force-bottle $FORMULAE` to check the SHA-256 in the bottled formulae match the uploaded files.
 4. Run `git push` to push the commits.
 
 To bottle a test build or pull request without `brew pull`:
@@ -29,5 +29,5 @@ To bottle a test build or pull request without `brew pull`:
 3. Run `git fetch --tags https://github.com/BrewTestBot/homebrew.git`
 4. For testing builds run `git merge testing-123` (where `123` is the testing job number). For pull requests builds run `git merge pr-45678` (where `45678` is the pull request number).
 5. Run `git rebase origin/master` to get rid of any nasty merge commits.
-6. Run `brew fetch --force-bottle $FORMULAE` to check the SHA-1 in the bottled formulae match the uploaded files.
+6. Run `brew fetch --force-bottle $FORMULAE` to check the SHA-256 in the bottled formulae match the uploaded files.
 7. Run `git push` to push the commits.
diff --git a/share/doc/homebrew/Formula-Cookbook.md b/share/doc/homebrew/Formula-Cookbook.md
index 3aa3fe6671..72073959f0 100644
--- a/share/doc/homebrew/Formula-Cookbook.md
+++ b/share/doc/homebrew/Formula-Cookbook.md
@@ -99,7 +99,7 @@ And opens it in your `$EDITOR`. It'll look like:
 class Foo < Formula
   url "http://example.com/foo-0.1.tar.gz"
   homepage ""
-  sha1 "1234567890ABCDEF1234567890ABCDEF"
+  sha256 "85cc828a96735bdafcf29eb6291ca91bac846579bcef7308536e0c875d6c81d7"
 
   # depends_on "cmake" => :build
 
@@ -257,7 +257,7 @@ If you're installing an application then please locally vendor all the language-
 class Foo < Formula
   resource "pycrypto" do
     url "https://pypi.python.org/packages/source/p/pycrypto/pycrypto-2.6.tar.gz"
-    sha1 "c17e41a80b3fbf2ee4e8f2d8bb9e28c5d08bbb84"
+    sha256 "85cc828a96735bdafcf29eb6291ca91bac846579bcef7308536e0c875d6c81d7"
   end
 
   def install
@@ -476,7 +476,7 @@ External patches can be declared using resource-style blocks:
 ```rb
 patch do
   url "https://example.com/example_patch.diff"
-  sha1 "deadbeefdeadbeefdeadbeefdeadbeefdeadbeef"
+  sha256 "85cc828a96735bdafcf29eb6291ca91bac846579bcef7308536e0c875d6c81d7"
 end
 ```
 
@@ -485,7 +485,7 @@ A strip level of -p1 is assumed. It can be overridden using a symbol argument:
 ```rb
 patch :p0 do
   url "https://example.com/example_patch.diff"
-  sha1 "deadbeefdeadbeefdeadbeefdeadbeefdeadbeef"
+  sha256 "85cc828a96735bdafcf29eb6291ca91bac846579bcef7308536e0c875d6c81d7"
 end
 ```
 
@@ -497,7 +497,7 @@ stable do
 
   patch do
     url "https://example.com/example_patch.diff"
-    sha1 "deadbeefdeadbeefdeadbeefdeadbeefdeadbeef"
+    sha256 "85cc828a96735bdafcf29eb6291ca91bac846579bcef7308536e0c875d6c81d7"
   end
 end
 ```
@@ -583,7 +583,7 @@ The "devel" spec (activated by passing `--devel`) is used for a project’s unst
 ```ruby
 devel do
   url "https://foo.com/foo-0.1.tar.gz"
-  sha1 "deadbeefdeadbeefdeadbeafdeadbeefdeadbeef"
+  sha256 "85cc828a96735bdafcf29eb6291ca91bac846579bcef7308536e0c875d6c81d7"
 end
 ```
 
@@ -895,7 +895,7 @@ Homebrew provides two Formula methods for launchd plist files. `plist_name` will
 
 ## Updating formulae
 
-Eventually a new version of the software will be released. In this case you should update the `url` and `sha1`/`sha256`. Please leave the `bottle do ... end`  block as-is; our CI system will update it when we pull your change.
+Eventually a new version of the software will be released. In this case you should update the `url` and `sha256`. Please leave the `bottle do ... end`  block as-is; our CI system will update it when we pull your change.
 
 Check if the formula you are updating is a dependency for any other formulae by running `brew uses UPDATED_FORMULA`. If it is a dependency please `brew reinstall` all the dependencies after it is installed and verify they work correctly.