diff --git a/CHANGELOG.md b/CHANGELOG.md
index e33d94249..33c418a08 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,21 +2,30 @@
 ## Significant changes
 - The clipboard integration has been revamped with explicit bindings. OS X clipboard support provided for out of the box in addition to X11. (#3061)
 
-# fish 2.3.1 (unreleased)
+---
+
+# fish 2.3.1 (released July 3, 2016)
+
+This is a functionality and bugfix release. This release does not contain all the changes to fish since the last release, but fixes a number of issues directly affecting users at present and includes a small number of new features.
 
 ## Significant changes
-- The `key_reader` utility was renamed to `fish_key_reader` and is now built by default. (#2991)
+- A new `fish_key_reader` binary for decoding interactive keypresses (#2991).
+- `fish_mode_prompt` has been updated to reflect the changes in the way the Vi input mode is set up (#3067), making this more reliable.
+- `fish_config` can now properly be launched from the OS X app bundle (#3140).
 
-## Other notable fixes and improvements
-- Paper over mayhem caused with missing `string` builtin while old versions of fish are still running moments after upgrading to fish 2.3 (#3057, #3065, #3125, #3141)
-- Fish is less confused about locales now than it was when 2.3.0 was released. (#3124, )
-- `fish_config` didn't work in fish.app (OS X) if one didn't already have fish installed by some other means. (#3140)
+## Notable fixes and improvements
+
+- Extra lines were sometimes inserted into the output under Windows (Cygwin and Microsoft Windows Subsystem for Linux) due to TTY timestamps not being updated (#2859).
+- The `string` builtin's `match` mode now handles the combination of `-rnv` (match, invert and count) correctly (#3098).
+- Improvements to TTY special character handling (#3064), locale handling (#3124) and terminal environment variable handling (#3060).
+- Work towards handling the terminal modes for external commands launched from initialisation files (#2980).
+- Ease the upgrade path from fish 2.2.0 and before by warning users to restart fish if the `string` builtin is not available (#3057).
 - `type -a` now syntax-colorizes function source output.
-- Improvements to `suspend` function (#3154), 
-- New completions for: alsamixer, godoc, gofmt, goimports, golint, gorename, ip, lscpu, mkdir, modinfo, netctl-auto, networkctl, poweroff, termite, udisksctl, xz
+- Added completions for `alsamixer`, `godoc`, `gofmt`, `goimports`, `gorename`, `lscpu`, `mkdir`, `modinfo`, `netctl-auto`, `poweroff`, `termite`, `udisksctl` and `xz` (#3123).
+- Improved completions for `apt` (#3097), `aura` (#3102),`git` (#3114), `npm` (#3158), `string` and `suspend` (#3154).
+
+---
 
-##Known issues 
-  
 # fish 2.3.0 (released May 20, 2016)
 
 There are no significant changes between 2.3.0 and 2.3b2.
diff --git a/osx/config.h b/osx/config.h
index 60ae03899..9f4f0bb16 100644
--- a/osx/config.h
+++ b/osx/config.h
@@ -167,7 +167,7 @@
 #define PACKAGE_NAME "fish"
 
 /* Define to the full name and version of this package. */
-#define PACKAGE_STRING "fish 2.3.0-git"
+#define PACKAGE_STRING "fish 2.3.1-git"
 
 /* Define to the one symbol short name of this package. */
 #define PACKAGE_TARNAME "fish"
@@ -176,7 +176,7 @@
 #define PACKAGE_URL ""
 
 /* Define to the version of this package. */
-#define PACKAGE_VERSION "2.3.0-git"
+#define PACKAGE_VERSION "2.3.1-git"
 
 /* The size of `wchar_t', as computed by sizeof. */
 #define SIZEOF_WCHAR_T 4
diff --git a/share/config.fish b/share/config.fish
index 35de799b2..2090b4421 100644
--- a/share/config.fish
+++ b/share/config.fish
@@ -18,17 +18,36 @@ function __fish_default_command_not_found_handler
 end
 
 if status --is-interactive
-	# Enable truecolor/24-bit support for select terminals
-	if not set -q NVIM_LISTEN_ADDRESS # Neovim will swallow the 24bit sequences, rendering text white
-		and begin
-			set -q KONSOLE_PROFILE_NAME # KDE's konsole
-			or string match -q -- "*:*" $ITERM_SESSION_ID # Supporting versions of iTerm2 will include a colon here
-			or string match -q -- "st-*" $TERM # suckless' st
-			or test "$VTE_VERSION" -ge 3600 # Should be all gtk3-vte-based terms after version 3.6.0.0
-			or test "$COLORTERM" = truecolor -o "$COLORTERM" = 24bit # slang expects this
+	# The user has seemingly explicitly launched an old fish with
+	# too-new scripts installed. 
+	if not contains "string" (builtin -n)
+		set -g __is_launched_without_string 1
+		# XXX nostring - fix old fish binaries with no `string' builtin.
+		# When executed on fish 2.2.0, the `else' block after this would
+		# force on 24-bit mode due to changes to in test behavior.
+		# These "XXX nostring" hacks were added for 2.3.1
+		set_color --bold
+		echo "You appear to be trying to launch an old fish binary with newer scripts "
+		echo "installed into" (set_color --underline)"$__fish_datadir" 
+		set_color normal
+		echo -e "\nThis is an unsupported configuration.\n"
+		set_color yellow
+		echo "You may need to uninstall and reinstall fish!"
+		set_color normal
+		# Remove this code when we've made it safer to upgrade fish.
+	else
+		# Enable truecolor/24-bit support for select terminals
+		if not set -q NVIM_LISTEN_ADDRESS # (Neovim will swallow the 24bit sequences, rendering text white)
+			and begin
+				set -q KONSOLE_PROFILE_NAME # KDE's konsole
+				or string match -q -- "*:*" $ITERM_SESSION_ID # Supporting versions of iTerm2 will include a colon here
+				or string match -q -- "st-*" $TERM # suckless' st
+				or test "$VTE_VERSION" -ge 3600 # Should be all gtk3-vte-based terms after version 3.6.0.0
+				or test "$COLORTERM" = truecolor -o "$COLORTERM" = 24bit # slang expects this
+			end
+			# Only set it if it isn't to allow override by setting to 0
+			set -q fish_term24bit; or set -g fish_term24bit 1
 		end
-		# Only set it if it isn't to allow override by setting to 0
-		set -q fish_term24bit; or set -g fish_term24bit 1
 	end
 else
 	# Hook up the default as the principal command_not_found handler
@@ -189,7 +208,7 @@ for file in $configdir/fish/conf.d/*.fish $__fish_sysconfdir/conf.d/*.fish $__ex
 end
 
 # Upgrade pre-existing abbreviations from the old "key=value" to the new "key value" syntax
-# This needs to be in share/config.fish because __fish_config_interactive is called after sourcing config.fish, which might contain abbr calls
+# This needs to be in share/config.fish because __fish_config_interactive is called after 2sourcing config.fish, which might contain abbr calls
 if not set -q __fish_init_2_3_0
 	set -l fab
 	for abb in $fish_user_abbreviations
diff --git a/share/functions/string.fish b/share/functions/string.fish
new file mode 100644
index 000000000..799258217
--- /dev/null
+++ b/share/functions/string.fish
@@ -0,0 +1,26 @@
+# XXX nostring
+if not contains string (builtin -n)
+    function string
+        if not set -q __is_launched_without_string
+            if status --is-interactive
+                # We've been autoloaded after fish < 2.3.0 upgraded to >= 2.3.1 - no string builtin
+                set_color --bold >&2
+                echo "Fish has been upgraded, and the scripts on your system are not compatible" >&2
+                echo "with this prior instance of fish. You can probably run:" >&2
+                set_color green >&2
+                echo -e "\n exec fish" >&2
+                set_color normal >&2
+                echo "… to replace this process with a new one in-place." >&2
+                set -g __is_launched_without_string 1
+            end
+        end
+        set PATH $__fish_bin_dir $PATH
+        set string_cmd string \'$argv\'
+
+        if fish -c 'contains string (builtin -n)'
+            fish -c "$string_cmd"
+        else
+            return 127
+        end
+    end
+end