diff --git a/Library/Homebrew/cmd/upgrade.rb b/Library/Homebrew/cmd/upgrade.rb
index 12833c15a0..3c90c0c957 100644
--- a/Library/Homebrew/cmd/upgrade.rb
+++ b/Library/Homebrew/cmd/upgrade.rb
@@ -5,14 +5,7 @@ module Homebrew
   def upgrade
     Homebrew.perform_preinstall_checks
 
-    if ARGV.include?("--all") || ARGV.named.empty?
-      unless ARGV.include? "--all"
-        opoo <<-EOS.undent
-          brew upgrade with no arguments will change behaviour soon!
-          It currently upgrades all formula but this will soon change to require '--all'.
-          Please update any workflows, documentation and scripts!
-        EOS
-      end
+    if ARGV.named.empty?
       outdated = Homebrew.outdated_brews(Formula.installed)
       exit 0 if outdated.empty?
     elsif ARGV.named.any?
@@ -27,11 +20,6 @@ module Homebrew
         end
       end
       exit 1 if outdated.empty?
-    else
-      # This will currently never be reached but is implemented to make the
-      # migration to --all easier in the future (as just the ARGV.named.empty?
-      # will need removed above).
-      odie "Either --all or one or more formulae must be specified!"
     end
 
     unless upgrade_pinned?
diff --git a/Library/Homebrew/manpages/brew.1.md b/Library/Homebrew/manpages/brew.1.md
index be9d47d788..e328ff9fde 100644
--- a/Library/Homebrew/manpages/brew.1.md
+++ b/Library/Homebrew/manpages/brew.1.md
@@ -403,15 +403,11 @@ Note that these flags should only appear after a command.
 
     If `--rebase` is specified then `git pull --rebase` is used.
 
-  * `upgrade [--all] [install-options]` [<formulae>]:
+  * `upgrade [install-options]` [<formulae>]:
     Upgrade outdated, unpinned brews.
 
     Options for the `install` command are also valid here.
 
-    If `--all` is passed, upgrade all formulae. This is currently the same
-    behaviour as without `--all` but soon `--all` will be required to upgrade
-    all formulae.
-
     If <formulae> are given, upgrade only the specified brews (but do so even
     if they are pinned; see `pin`, `unpin`).
 
diff --git a/share/man/man1/brew.1 b/share/man/man1/brew.1
index 1d7b221998..bcd995d2ac 100644
--- a/share/man/man1/brew.1
+++ b/share/man/man1/brew.1
@@ -432,16 +432,13 @@ Fetch the newest version of Homebrew and all formulae from GitHub using \fBgit\f
 If \fB\-\-rebase\fR is specified then \fBgit pull \-\-rebase\fR is used\.
 .
 .TP
-\fBupgrade [\-\-all] [install\-options]\fR [\fIformulae\fR]
+\fBupgrade [install\-options]\fR [\fIformulae\fR]
 Upgrade outdated, unpinned brews\.
 .
 .IP
 Options for the \fBinstall\fR command are also valid here\.
 .
 .IP
-If \fB\-\-all\fR is passed, upgrade all formulae\. This is currently the same behaviour as without \fB\-\-all\fR but soon \fB\-\-all\fR will be required to upgrade all formulae\.
-.
-.IP
 If \fIformulae\fR are given, upgrade only the specified brews (but do so even if they are pinned; see \fBpin\fR, \fBunpin\fR)\.
 .
 .TP