diff --git a/.rubocop.yml b/.rubocop.yml
index 9e0792f..97facac 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -2,29 +2,29 @@
 #   Enabled: true
 
 AllCops:
-	TargetRubyVersion: 2.3
-	Include:
-		- '**/Rakefile'
-		- '**/config.ru'
-		- '**/Gemfile'
+  TargetRubyVersion: 2.3
+  Include:
+    - '**/Rakefile'
+    - '**/config.ru'
+    - '**/Gemfile'
 
 Metrics/LineLength:
-	Max: 120
+  Max: 120
 
 Style/Documentation:
-	Enabled: false
+  Enabled: false
 
 Style/DotPosition:
-	EnforcedStyle: trailing
+  EnforcedStyle: trailing
 
 Style/FrozenStringLiteralComment:
-	Enabled: false
+  Enabled: false
 
 Style/Lambda:
-	Enabled: false
+  Enabled: false
 
 Style/MultilineMethodCallIndentation:
-	EnforcedStyle: indented
+  EnforcedStyle: indented
 
 Style/TrailingUnderscoreVariable:
-	Enabled: false
+  Enabled: false
diff --git a/CHANGELOG.md b/CHANGELOG.md
index ac0f8e6..fb15b88 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,14 +1,21 @@
 # Changelog
 
+## v0.4.1
+- Switch to [[ and (( conditionals instead of [ (#257)
+- Avoid warnnestedvar warnings with `typeset -g` (#275)
+- Replace tabs with spaces in yaml (#268)
+- Clean up and fix escaping of special characters (#267)
+- Add `emacs-forward-word` to default list of partial accept widgets (#246)
+
 ## v0.4.0
 - High-level integration tests using RSpec and tmux
 - Add continuous integration with Circle CI
-- Experimental support for asynchronous suggestions (#)
-- Fix problems with multi-line suggestions (#)
+- Experimental support for asynchronous suggestions (#170)
+- Fix problems with multi-line suggestions (#225)
 - Optimize case where manually typing in suggestion
-- Avoid wrapping any zle-* widgets (#)
+- Avoid wrapping any zle-* widgets (#206)
 - Remove support for deprecated options from v0.0.x
-- Handle history entries that begin with dashes (#)
+- Handle history entries that begin with dashes
 - Gracefully handle being sourced multiple times (#126)
 - Add enable/disable/toggle widgets to disable/enable suggestions (#219)
 
diff --git a/Makefile b/Makefile
index d5d162c..5402b7f 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,6 @@ SRC_DIR    := ./src
 SRC_FILES := \
 	$(SRC_DIR)/setup.zsh \
 	$(SRC_DIR)/config.zsh \
-	$(SRC_DIR)/util.zsh \
 	$(SRC_DIR)/features.zsh \
 	$(SRC_DIR)/bind.zsh \
 	$(SRC_DIR)/highlight.zsh \
diff --git a/README.md b/README.md
index 4df4e90..8aedb31 100644
--- a/README.md
+++ b/README.md
@@ -16,7 +16,7 @@ It suggests commands as you type, based on command history.
 1. Clone this repository somewhere on your machine. This guide will assume `~/.zsh/zsh-autosuggestions`.
 
     ```sh
-    git clone git://github.com/zsh-users/zsh-autosuggestions ~/.zsh/zsh-autosuggestions
+    git clone https://github.com/zsh-users/zsh-autosuggestions ~/.zsh/zsh-autosuggestions
     ```
 
 2. Add the following to your `.zshrc`:
@@ -33,7 +33,7 @@ It suggests commands as you type, based on command history.
 1. Clone this repository into `$ZSH_CUSTOM/plugins` (by default `~/.oh-my-zsh/custom/plugins`)
 
     ```sh
-    git clone git://github.com/zsh-users/zsh-autosuggestions $ZSH_CUSTOM/plugins/zsh-autosuggestions
+    git clone https://github.com/zsh-users/zsh-autosuggestions $ZSH_CUSTOM/plugins/zsh-autosuggestions
     ```
 
 2. Add the plugin to the list of plugins for Oh My Zsh to load:
diff --git a/VERSION b/VERSION
index fb7a04c..5aff472 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-v0.4.0
+v0.4.1
diff --git a/spec/integrations/bracketed_paste_magic_spec.rb b/spec/integrations/bracketed_paste_magic_spec.rb
index f01b0e0..64092ad 100644
--- a/spec/integrations/bracketed_paste_magic_spec.rb
+++ b/spec/integrations/bracketed_paste_magic_spec.rb
@@ -23,14 +23,5 @@ describe 'pasting using bracketed-paste-magic' do
         expect(session.content).to eq("echo #{'a' * 60}")
       end
     end
-
-    it 'shows a suggestion after a non-modifying keystroke' do
-      with_history('echo hello') do
-        session.paste_string('echo')
-        sleep 1
-        session.send_keys('left')
-        wait_for { session.content }.to eq('echo hello')
-      end
-    end
   end
 end
diff --git a/spec/integrations/rebound_bracket_spec.rb b/spec/integrations/rebound_bracket_spec.rb
new file mode 100644
index 0000000..8b420f0
--- /dev/null
+++ b/spec/integrations/rebound_bracket_spec.rb
@@ -0,0 +1,13 @@
+describe 'rebinding [' do
+  context 'initialized before sourcing the plugin' do
+    before do
+      session.run_command("function [ { $commands[\\[] \"$@\" }")
+      session.clear_screen
+    end
+
+    it 'executes the custom behavior and the built-in behavior' do
+      session.send_string('asdf')
+      wait_for { session.content }.to eq('asdf')
+    end
+  end
+end
diff --git a/spec/special_characters_spec.rb b/spec/special_characters_spec.rb
deleted file mode 100644
index ce7810b..0000000
--- a/spec/special_characters_spec.rb
+++ /dev/null
@@ -1,60 +0,0 @@
-describe 'a special character in the buffer' do
-  it 'should be treated like any other character' do
-    with_history('echo "hello*"', 'echo "hello."') do
-      session.send_string('echo "hello*')
-      wait_for { session.content }.to eq('echo "hello*"')
-    end
-
-    with_history('echo "hello?"', 'echo "hello."') do
-      session.send_string('echo "hello?')
-      wait_for { session.content }.to eq('echo "hello?"')
-    end
-
-    with_history('echo "hello\nworld"') do
-      session.send_string('echo "hello\\')
-      wait_for { session.content }.to eq('echo "hello\nworld"')
-    end
-
-    with_history('echo "\\\\"') do
-      session.send_string('echo "\\\\')
-      wait_for { session.content }.to eq('echo "\\\\"')
-    end
-
-    with_history('echo ~/foo') do
-      session.send_string('echo ~')
-      wait_for { session.content }.to eq('echo ~/foo')
-    end
-
-    with_history('echo "$(ls foo)"') do
-      session.send_string('echo "$(')
-      wait_for { session.content }.to eq('echo "$(ls foo)"')
-    end
-
-    with_history('echo "$history[123]"') do
-      session.send_string('echo "$history[')
-      wait_for { session.content }.to eq('echo "$history[123]"')
-      session.send_string('123]')
-      wait_for { session.content }.to eq('echo "$history[123]"')
-    end
-
-    with_history('echo "#yolo"') do
-      session.send_string('echo "#')
-      wait_for { session.content }.to eq('echo "#yolo"')
-    end
-
-    with_history('echo "#foo"', 'echo $#abc') do
-      session.send_string('echo "#')
-      wait_for { session.content }.to eq('echo "#foo"')
-    end
-
-    with_history('echo "^A"', 'echo "^B"') do
-      session.send_string('echo "^A')
-      wait_for { session.content }.to eq('echo "^A"')
-    end
-
-    with_history('-foo() {}') do
-      session.send_string('-')
-      wait_for { session.content }.to eq('-foo() {}')
-    end
-  end
-end
diff --git a/spec/strategies/default_spec.rb b/spec/strategies/default_spec.rb
index 94f3450..89321f3 100644
--- a/spec/strategies/default_spec.rb
+++ b/spec/strategies/default_spec.rb
@@ -1,3 +1,5 @@
+require 'strategies/special_characters_helper'
+
 describe 'the default suggestion strategy' do
   it 'suggests the last matching history entry' do
     with_history('ls foo', 'ls bar', 'echo baz') do
@@ -5,4 +7,6 @@ describe 'the default suggestion strategy' do
       wait_for { session.content }.to eq('ls bar')
     end
   end
+
+  include_examples 'special characters'
 end
diff --git a/spec/strategies/match_prev_cmd_spec.rb b/spec/strategies/match_prev_cmd_spec.rb
index 21be712..f1596ba 100644
--- a/spec/strategies/match_prev_cmd_spec.rb
+++ b/spec/strategies/match_prev_cmd_spec.rb
@@ -1,3 +1,5 @@
+require 'strategies/special_characters_helper'
+
 describe 'the match_prev_cmd strategy' do
   let(:options) { ['ZSH_AUTOSUGGEST_STRATEGY=match_prev_cmd'] }
 
@@ -14,4 +16,6 @@ describe 'the match_prev_cmd strategy' do
       wait_for { session.content }.to eq('ls bar')
     end
   end
+
+  include_examples 'special characters'
 end
diff --git a/spec/strategies/special_characters_helper.rb b/spec/strategies/special_characters_helper.rb
new file mode 100644
index 0000000..8771861
--- /dev/null
+++ b/spec/strategies/special_characters_helper.rb
@@ -0,0 +1,62 @@
+shared_examples 'special characters' do
+  describe 'a special character in the buffer' do
+    it 'should be treated like any other character' do
+      with_history('echo "hello*"', 'echo "hello."') do
+        session.send_string('echo "hello*')
+        wait_for { session.content }.to eq('echo "hello*"')
+      end
+
+      with_history('echo "hello?"', 'echo "hello."') do
+        session.send_string('echo "hello?')
+        wait_for { session.content }.to eq('echo "hello?"')
+      end
+
+      with_history('echo "hello\nworld"') do
+        session.send_string('echo "hello\\')
+        wait_for { session.content }.to eq('echo "hello\nworld"')
+      end
+
+      with_history('echo "\\\\"') do
+        session.send_string('echo "\\\\')
+        wait_for { session.content }.to eq('echo "\\\\"')
+      end
+
+      with_history('echo ~/foo') do
+        session.send_string('echo ~')
+        wait_for { session.content }.to eq('echo ~/foo')
+      end
+
+      with_history('echo "$(ls foo)"') do
+        session.send_string('echo "$(')
+        wait_for { session.content }.to eq('echo "$(ls foo)"')
+      end
+
+      with_history('echo "$history[123]"') do
+        session.send_string('echo "$history[')
+        wait_for { session.content }.to eq('echo "$history[123]"')
+        session.send_string('123]')
+        wait_for { session.content }.to eq('echo "$history[123]"')
+      end
+
+      with_history('echo "#yolo"') do
+        session.send_string('echo "#')
+        wait_for { session.content }.to eq('echo "#yolo"')
+      end
+
+      with_history('echo "#foo"', 'echo $#abc') do
+        session.send_string('echo "#')
+        wait_for { session.content }.to eq('echo "#foo"')
+      end
+
+      with_history('echo "^A"', 'echo "^B"') do
+        session.send_string('echo "^A')
+        wait_for { session.content }.to eq('echo "^A"')
+      end
+
+      with_history('-foo() {}') do
+        session.send_string('-')
+        wait_for { session.content }.to eq('-foo() {}')
+      end
+    end
+  end
+end
diff --git a/src/async.zsh b/src/async.zsh
index 124c9ac..1d1e76d 100644
--- a/src/async.zsh
+++ b/src/async.zsh
@@ -63,7 +63,7 @@ _zsh_autosuggest_async_pty_create() {
 	typeset -h REPLY
 
 	# If we won't get a fd back from zpty, try to guess it
-	if [ $_ZSH_AUTOSUGGEST_ZPTY_RETURNS_FD -eq 0 ]; then
+	if (( ! $_ZSH_AUTOSUGGEST_ZPTY_RETURNS_FD )); then
 		integer -l zptyfd
 		exec {zptyfd}>&1  # Open a new file descriptor (above 10).
 		exec {zptyfd}>&-  # Close it so it's free to be used by zpty.
diff --git a/src/bind.zsh b/src/bind.zsh
index d8629f1..ed9a977 100644
--- a/src/bind.zsh
+++ b/src/bind.zsh
@@ -10,14 +10,14 @@ _zsh_autosuggest_incr_bind_count() {
 		_ZSH_AUTOSUGGEST_BIND_COUNTS[$1]=1
 	fi
 
-	bind_count=$_ZSH_AUTOSUGGEST_BIND_COUNTS[$1]
+	typeset -gi bind_count=$_ZSH_AUTOSUGGEST_BIND_COUNTS[$1]
 }
 
 _zsh_autosuggest_get_bind_count() {
 	if ((${+_ZSH_AUTOSUGGEST_BIND_COUNTS[$1]})); then
-		bind_count=$_ZSH_AUTOSUGGEST_BIND_COUNTS[$1]
+		typeset -gi bind_count=$_ZSH_AUTOSUGGEST_BIND_COUNTS[$1]
 	else
-		bind_count=0
+		typeset -gi bind_count=0
 	fi
 }
 
@@ -88,13 +88,13 @@ _zsh_autosuggest_bind_widgets() {
 
 	# Find every widget we might want to bind and bind it appropriately
 	for widget in ${${(f)"$(builtin zle -la)"}:#${(j:|:)~ignore_widgets}}; do
-		if [ ${ZSH_AUTOSUGGEST_CLEAR_WIDGETS[(r)$widget]} ]; then
+		if [[ -n ${ZSH_AUTOSUGGEST_CLEAR_WIDGETS[(r)$widget]} ]]; then
 			_zsh_autosuggest_bind_widget $widget clear
-		elif [ ${ZSH_AUTOSUGGEST_ACCEPT_WIDGETS[(r)$widget]} ]; then
+		elif [[ -n ${ZSH_AUTOSUGGEST_ACCEPT_WIDGETS[(r)$widget]} ]]; then
 			_zsh_autosuggest_bind_widget $widget accept
-		elif [ ${ZSH_AUTOSUGGEST_EXECUTE_WIDGETS[(r)$widget]} ]; then
+		elif [[ -n ${ZSH_AUTOSUGGEST_EXECUTE_WIDGETS[(r)$widget]} ]]; then
 			_zsh_autosuggest_bind_widget $widget execute
-		elif [ ${ZSH_AUTOSUGGEST_PARTIAL_ACCEPT_WIDGETS[(r)$widget]} ]; then
+		elif [[ -n ${ZSH_AUTOSUGGEST_PARTIAL_ACCEPT_WIDGETS[(r)$widget]} ]]; then
 			_zsh_autosuggest_bind_widget $widget partial_accept
 		else
 			# Assume any unspecified widget might modify the buffer
@@ -106,13 +106,13 @@ _zsh_autosuggest_bind_widgets() {
 # Given the name of an original widget and args, invoke it, if it exists
 _zsh_autosuggest_invoke_original_widget() {
 	# Do nothing unless called with at least one arg
-	[ $# -gt 0 ] || return
+	(( $# )) || return
 
 	local original_widget_name="$1"
 
 	shift
 
-	if [ $widgets[$original_widget_name] ]; then
+	if (( ${+widgets[$original_widget_name]} )); then
 		zle $original_widget_name -- $@
 	fi
 }
diff --git a/src/config.zsh b/src/config.zsh
index c7fc55a..ba694c0 100644
--- a/src/config.zsh
+++ b/src/config.zsh
@@ -42,6 +42,7 @@ ZSH_AUTOSUGGEST_EXECUTE_WIDGETS=(
 # Widgets that accept the suggestion as far as the cursor moves
 ZSH_AUTOSUGGEST_PARTIAL_ACCEPT_WIDGETS=(
 	forward-word
+	emacs-forward-word
 	vi-forward-word
 	vi-forward-word-end
 	vi-forward-blank-word
diff --git a/src/highlight.zsh b/src/highlight.zsh
index a8ff08a..273c03d 100644
--- a/src/highlight.zsh
+++ b/src/highlight.zsh
@@ -7,7 +7,7 @@
 _zsh_autosuggest_highlight_reset() {
 	typeset -g _ZSH_AUTOSUGGEST_LAST_HIGHLIGHT
 
-	if [ -n "$_ZSH_AUTOSUGGEST_LAST_HIGHLIGHT" ]; then
+	if [[ -n "$_ZSH_AUTOSUGGEST_LAST_HIGHLIGHT" ]]; then
 		region_highlight=("${(@)region_highlight:#$_ZSH_AUTOSUGGEST_LAST_HIGHLIGHT}")
 		unset _ZSH_AUTOSUGGEST_LAST_HIGHLIGHT
 	fi
@@ -17,8 +17,8 @@ _zsh_autosuggest_highlight_reset() {
 _zsh_autosuggest_highlight_apply() {
 	typeset -g _ZSH_AUTOSUGGEST_LAST_HIGHLIGHT
 
-	if [ $#POSTDISPLAY -gt 0 ]; then
-		_ZSH_AUTOSUGGEST_LAST_HIGHLIGHT="$#BUFFER $(($#BUFFER + $#POSTDISPLAY)) $ZSH_AUTOSUGGEST_HIGHLIGHT_STYLE"
+	if (( $#POSTDISPLAY )); then
+		typeset -g _ZSH_AUTOSUGGEST_LAST_HIGHLIGHT="$#BUFFER $(($#BUFFER + $#POSTDISPLAY)) $ZSH_AUTOSUGGEST_HIGHLIGHT_STYLE"
 		region_highlight+=("$_ZSH_AUTOSUGGEST_LAST_HIGHLIGHT")
 	else
 		unset _ZSH_AUTOSUGGEST_LAST_HIGHLIGHT
diff --git a/src/start.zsh b/src/start.zsh
index 6fa8ce9..6f48ab6 100644
--- a/src/start.zsh
+++ b/src/start.zsh
@@ -15,7 +15,7 @@ _zsh_autosuggest_start() {
 	# to the widget list variables to take effect on the next precmd.
 	add-zsh-hook precmd _zsh_autosuggest_bind_widgets
 
-	if [ -n "${ZSH_AUTOSUGGEST_USE_ASYNC+x}" ]; then
+	if [[ -n "${ZSH_AUTOSUGGEST_USE_ASYNC+x}" ]]; then
 		_zsh_autosuggest_async_start
 	fi
 }
diff --git a/src/strategies/default.zsh b/src/strategies/default.zsh
index 60c0494..17bf65d 100644
--- a/src/strategies/default.zsh
+++ b/src/strategies/default.zsh
@@ -7,19 +7,9 @@
 #
 
 _zsh_autosuggest_strategy_default() {
-	# Reset options to defaults and enable LOCAL_OPTIONS
-	emulate -L zsh
-
-	# Enable globbing flags so that we can use (#m)
-	setopt EXTENDED_GLOB
-
-	# Escape backslashes and all of the glob operators so we can use
-	# this string as a pattern to search the $history associative array.
-	# - (#m) globbing flag enables setting references for match data
-	local prefix="${1//(#m)[\\*?[\]<>()|^~#]/\\$MATCH}"
+	local prefix="$1"
 
 	# Get the history items that match
 	# - (r) subscript flag makes the pattern match on values
-	suggestion="${history[(r)$prefix*]}"
-
+	typeset -g suggestion="${history[(r)${(b)prefix}*]}"
 }
diff --git a/src/strategies/match_prev_cmd.zsh b/src/strategies/match_prev_cmd.zsh
index ee26346..8a84728 100644
--- a/src/strategies/match_prev_cmd.zsh
+++ b/src/strategies/match_prev_cmd.zsh
@@ -21,18 +21,18 @@
 # `HIST_EXPIRE_DUPS_FIRST`.
 
 _zsh_autosuggest_strategy_match_prev_cmd() {
-	local prefix="${1//(#m)[\\()\[\]|*?~]/\\$MATCH}"
+	local prefix="$1"
 
 	# Get all history event numbers that correspond to history
 	# entries that match pattern $prefix*
 	local history_match_keys
-	history_match_keys=(${(k)history[(R)$prefix*]})
+	history_match_keys=(${(k)history[(R)${(b)prefix}*]})
 
 	# By default we use the first history number (most recent history entry)
 	local histkey="${history_match_keys[1]}"
 
 	# Get the previously executed command
-	local prev_cmd="$(_zsh_autosuggest_escape_command "${history[$((HISTCMD-1))]}")"
+	local prev_cmd="${history[$((HISTCMD-1))]}"
 
 	# Iterate up to the first 200 history event numbers that match $prefix
 	for key in "${(@)history_match_keys[1,200]}"; do
@@ -48,5 +48,5 @@ _zsh_autosuggest_strategy_match_prev_cmd() {
 	done
 
 	# Give back the matched history entry
-	suggestion="$history[$histkey]"
+	typeset -g suggestion="$history[$histkey]"
 }
diff --git a/src/util.zsh b/src/util.zsh
deleted file mode 100644
index 1f55d36..0000000
--- a/src/util.zsh
+++ /dev/null
@@ -1,11 +0,0 @@
-
-#--------------------------------------------------------------------#
-# Utility Functions                                                  #
-#--------------------------------------------------------------------#
-
-_zsh_autosuggest_escape_command() {
-	setopt localoptions EXTENDED_GLOB
-
-	# Escape special chars in the string (requires EXTENDED_GLOB)
-	echo -E "${1//(#m)[\"\'\\()\[\]|*?~]/\\$MATCH}"
-}
diff --git a/src/widgets.zsh b/src/widgets.zsh
index aa3f248..8a31133 100644
--- a/src/widgets.zsh
+++ b/src/widgets.zsh
@@ -13,14 +13,14 @@ _zsh_autosuggest_disable() {
 _zsh_autosuggest_enable() {
 	unset _ZSH_AUTOSUGGEST_DISABLED
 
-	if [ $#BUFFER -gt 0 ]; then
+	if (( $#BUFFER )); then
 		_zsh_autosuggest_fetch
 	fi
 }
 
 # Toggle suggestions (enable/disable)
 _zsh_autosuggest_toggle() {
-	if [ -n "${_ZSH_AUTOSUGGEST_DISABLED+x}" ]; then
+	if [[ -n "${_ZSH_AUTOSUGGEST_DISABLED+x}" ]]; then
 		_zsh_autosuggest_enable
 	else
 		_zsh_autosuggest_disable
@@ -39,7 +39,7 @@ _zsh_autosuggest_clear() {
 _zsh_autosuggest_modify() {
 	local -i retval
 
-	# Only added to zsh very recently
+	# Only available in zsh >= 5.4
 	local -i KEYS_QUEUED_COUNT
 
 	# Save the contents of the buffer/postdisplay
@@ -54,35 +54,35 @@ _zsh_autosuggest_modify() {
 	retval=$?
 
 	# Don't fetch a new suggestion if there's more input to be read immediately
-	if [[ $PENDING > 0 ]] || [[ $KEYS_QUEUED_COUNT > 0 ]]; then
+	if (( $PENDING > 0 )) || (( $KEYS_QUEUED_COUNT > 0 )); then
 		return $retval
 	fi
 
 	# Optimize if manually typing in the suggestion
-	if [ $#BUFFER -gt $#orig_buffer ]; then
+	if (( $#BUFFER > $#orig_buffer )); then
 		local added=${BUFFER#$orig_buffer}
 
 		# If the string added matches the beginning of the postdisplay
-		if [ "$added" = "${orig_postdisplay:0:$#added}" ]; then
+		if [[ "$added" = "${orig_postdisplay:0:$#added}" ]]; then
 			POSTDISPLAY="${orig_postdisplay:$#added}"
 			return $retval
 		fi
 	fi
 
 	# Don't fetch a new suggestion if the buffer hasn't changed
-	if [ "$BUFFER" = "$orig_buffer" ]; then
+	if [[ "$BUFFER" = "$orig_buffer" ]]; then
 		POSTDISPLAY="$orig_postdisplay"
 		return $retval
 	fi
 
 	# Bail out if suggestions are disabled
-	if [ -n "${_ZSH_AUTOSUGGEST_DISABLED+x}" ]; then
+	if [[ -n "${_ZSH_AUTOSUGGEST_DISABLED+x}" ]]; then
 		return $?
 	fi
 
 	# Get a new suggestion if the buffer is not empty after modification
-	if [ $#BUFFER -gt 0 ]; then
-		if [ -z "$ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE" -o $#BUFFER -le "$ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE" ]; then
+	if (( $#BUFFER > 0 )); then
+		if [[ -z "$ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE" ]] || (( $#BUFFER <= $ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE )); then
 			_zsh_autosuggest_fetch
 		fi
 	fi
@@ -105,7 +105,7 @@ _zsh_autosuggest_fetch() {
 _zsh_autosuggest_suggest() {
 	local suggestion="$1"
 
-	if [ -n "$suggestion" ] && [ $#BUFFER -gt 0 ]; then
+	if [[ -n "$suggestion" ]] && (( $#BUFFER )); then
 		POSTDISPLAY="${suggestion#$BUFFER}"
 	else
 		unset POSTDISPLAY
@@ -118,12 +118,12 @@ _zsh_autosuggest_accept() {
 
 	# When vicmd keymap is active, the cursor can't move all the way
 	# to the end of the buffer
-	if [ "$KEYMAP" = "vicmd" ]; then
+	if [[ "$KEYMAP" = "vicmd" ]]; then
 		max_cursor_pos=$((max_cursor_pos - 1))
 	fi
 
 	# Only accept if the cursor is at the end of the buffer
-	if [ $CURSOR -eq $max_cursor_pos ]; then
+	if [[ $CURSOR = $max_cursor_pos ]]; then
 		# Add the suggestion to the buffer
 		BUFFER="$BUFFER$POSTDISPLAY"
 
@@ -165,7 +165,7 @@ _zsh_autosuggest_partial_accept() {
 	retval=$?
 
 	# If we've moved past the end of the original buffer
-	if [ $CURSOR -gt $#original_buffer ]; then
+	if (( $CURSOR > $#original_buffer )); then
 		# Set POSTDISPLAY to text right of the cursor
 		POSTDISPLAY="$RBUFFER"
 
diff --git a/zsh-autosuggestions.zsh b/zsh-autosuggestions.zsh
index 0d389ec..fadbac7 100644
--- a/zsh-autosuggestions.zsh
+++ b/zsh-autosuggestions.zsh
@@ -1,6 +1,6 @@
 # Fish-like fast/unobtrusive autosuggestions for zsh.
 # https://github.com/zsh-users/zsh-autosuggestions
-# v0.4.0
+# v0.4.1
 # Copyright (c) 2013 Thiago de Arruda
 # Copyright (c) 2016-2017 Eric Freese
 # 
@@ -78,6 +78,7 @@ ZSH_AUTOSUGGEST_EXECUTE_WIDGETS=(
 # Widgets that accept the suggestion as far as the cursor moves
 ZSH_AUTOSUGGEST_PARTIAL_ACCEPT_WIDGETS=(
 	forward-word
+	emacs-forward-word
 	vi-forward-word
 	vi-forward-word-end
 	vi-forward-blank-word
@@ -100,17 +101,6 @@ ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE=
 # Pty name for calculating autosuggestions asynchronously
 ZSH_AUTOSUGGEST_ASYNC_PTY_NAME=zsh_autosuggest_pty
 
-#--------------------------------------------------------------------#
-# Utility Functions                                                  #
-#--------------------------------------------------------------------#
-
-_zsh_autosuggest_escape_command() {
-	setopt localoptions EXTENDED_GLOB
-
-	# Escape special chars in the string (requires EXTENDED_GLOB)
-	echo -E "${1//(#m)[\"\'\\()\[\]|*?~]/\\$MATCH}"
-}
-
 #--------------------------------------------------------------------#
 # Feature Detection                                                  #
 #--------------------------------------------------------------------#
@@ -141,14 +131,14 @@ _zsh_autosuggest_incr_bind_count() {
 		_ZSH_AUTOSUGGEST_BIND_COUNTS[$1]=1
 	fi
 
-	bind_count=$_ZSH_AUTOSUGGEST_BIND_COUNTS[$1]
+	typeset -gi bind_count=$_ZSH_AUTOSUGGEST_BIND_COUNTS[$1]
 }
 
 _zsh_autosuggest_get_bind_count() {
 	if ((${+_ZSH_AUTOSUGGEST_BIND_COUNTS[$1]})); then
-		bind_count=$_ZSH_AUTOSUGGEST_BIND_COUNTS[$1]
+		typeset -gi bind_count=$_ZSH_AUTOSUGGEST_BIND_COUNTS[$1]
 	else
-		bind_count=0
+		typeset -gi bind_count=0
 	fi
 }
 
@@ -219,13 +209,13 @@ _zsh_autosuggest_bind_widgets() {
 
 	# Find every widget we might want to bind and bind it appropriately
 	for widget in ${${(f)"$(builtin zle -la)"}:#${(j:|:)~ignore_widgets}}; do
-		if [ ${ZSH_AUTOSUGGEST_CLEAR_WIDGETS[(r)$widget]} ]; then
+		if [[ -n ${ZSH_AUTOSUGGEST_CLEAR_WIDGETS[(r)$widget]} ]]; then
 			_zsh_autosuggest_bind_widget $widget clear
-		elif [ ${ZSH_AUTOSUGGEST_ACCEPT_WIDGETS[(r)$widget]} ]; then
+		elif [[ -n ${ZSH_AUTOSUGGEST_ACCEPT_WIDGETS[(r)$widget]} ]]; then
 			_zsh_autosuggest_bind_widget $widget accept
-		elif [ ${ZSH_AUTOSUGGEST_EXECUTE_WIDGETS[(r)$widget]} ]; then
+		elif [[ -n ${ZSH_AUTOSUGGEST_EXECUTE_WIDGETS[(r)$widget]} ]]; then
 			_zsh_autosuggest_bind_widget $widget execute
-		elif [ ${ZSH_AUTOSUGGEST_PARTIAL_ACCEPT_WIDGETS[(r)$widget]} ]; then
+		elif [[ -n ${ZSH_AUTOSUGGEST_PARTIAL_ACCEPT_WIDGETS[(r)$widget]} ]]; then
 			_zsh_autosuggest_bind_widget $widget partial_accept
 		else
 			# Assume any unspecified widget might modify the buffer
@@ -237,13 +227,13 @@ _zsh_autosuggest_bind_widgets() {
 # Given the name of an original widget and args, invoke it, if it exists
 _zsh_autosuggest_invoke_original_widget() {
 	# Do nothing unless called with at least one arg
-	[ $# -gt 0 ] || return
+	(( $# )) || return
 
 	local original_widget_name="$1"
 
 	shift
 
-	if [ $widgets[$original_widget_name] ]; then
+	if (( ${+widgets[$original_widget_name]} )); then
 		zle $original_widget_name -- $@
 	fi
 }
@@ -256,7 +246,7 @@ _zsh_autosuggest_invoke_original_widget() {
 _zsh_autosuggest_highlight_reset() {
 	typeset -g _ZSH_AUTOSUGGEST_LAST_HIGHLIGHT
 
-	if [ -n "$_ZSH_AUTOSUGGEST_LAST_HIGHLIGHT" ]; then
+	if [[ -n "$_ZSH_AUTOSUGGEST_LAST_HIGHLIGHT" ]]; then
 		region_highlight=("${(@)region_highlight:#$_ZSH_AUTOSUGGEST_LAST_HIGHLIGHT}")
 		unset _ZSH_AUTOSUGGEST_LAST_HIGHLIGHT
 	fi
@@ -266,8 +256,8 @@ _zsh_autosuggest_highlight_reset() {
 _zsh_autosuggest_highlight_apply() {
 	typeset -g _ZSH_AUTOSUGGEST_LAST_HIGHLIGHT
 
-	if [ $#POSTDISPLAY -gt 0 ]; then
-		_ZSH_AUTOSUGGEST_LAST_HIGHLIGHT="$#BUFFER $(($#BUFFER + $#POSTDISPLAY)) $ZSH_AUTOSUGGEST_HIGHLIGHT_STYLE"
+	if (( $#POSTDISPLAY )); then
+		typeset -g _ZSH_AUTOSUGGEST_LAST_HIGHLIGHT="$#BUFFER $(($#BUFFER + $#POSTDISPLAY)) $ZSH_AUTOSUGGEST_HIGHLIGHT_STYLE"
 		region_highlight+=("$_ZSH_AUTOSUGGEST_LAST_HIGHLIGHT")
 	else
 		unset _ZSH_AUTOSUGGEST_LAST_HIGHLIGHT
@@ -288,14 +278,14 @@ _zsh_autosuggest_disable() {
 _zsh_autosuggest_enable() {
 	unset _ZSH_AUTOSUGGEST_DISABLED
 
-	if [ $#BUFFER -gt 0 ]; then
+	if (( $#BUFFER )); then
 		_zsh_autosuggest_fetch
 	fi
 }
 
 # Toggle suggestions (enable/disable)
 _zsh_autosuggest_toggle() {
-	if [ -n "${_ZSH_AUTOSUGGEST_DISABLED+x}" ]; then
+	if [[ -n "${_ZSH_AUTOSUGGEST_DISABLED+x}" ]]; then
 		_zsh_autosuggest_enable
 	else
 		_zsh_autosuggest_disable
@@ -314,7 +304,7 @@ _zsh_autosuggest_clear() {
 _zsh_autosuggest_modify() {
 	local -i retval
 
-	# Only added to zsh very recently
+	# Only available in zsh >= 5.4
 	local -i KEYS_QUEUED_COUNT
 
 	# Save the contents of the buffer/postdisplay
@@ -329,35 +319,35 @@ _zsh_autosuggest_modify() {
 	retval=$?
 
 	# Don't fetch a new suggestion if there's more input to be read immediately
-	if [[ $PENDING > 0 ]] || [[ $KEYS_QUEUED_COUNT > 0 ]]; then
+	if (( $PENDING > 0 )) || (( $KEYS_QUEUED_COUNT > 0 )); then
 		return $retval
 	fi
 
 	# Optimize if manually typing in the suggestion
-	if [ $#BUFFER -gt $#orig_buffer ]; then
+	if (( $#BUFFER > $#orig_buffer )); then
 		local added=${BUFFER#$orig_buffer}
 
 		# If the string added matches the beginning of the postdisplay
-		if [ "$added" = "${orig_postdisplay:0:$#added}" ]; then
+		if [[ "$added" = "${orig_postdisplay:0:$#added}" ]]; then
 			POSTDISPLAY="${orig_postdisplay:$#added}"
 			return $retval
 		fi
 	fi
 
 	# Don't fetch a new suggestion if the buffer hasn't changed
-	if [ "$BUFFER" = "$orig_buffer" ]; then
+	if [[ "$BUFFER" = "$orig_buffer" ]]; then
 		POSTDISPLAY="$orig_postdisplay"
 		return $retval
 	fi
 
 	# Bail out if suggestions are disabled
-	if [ -n "${_ZSH_AUTOSUGGEST_DISABLED+x}" ]; then
+	if [[ -n "${_ZSH_AUTOSUGGEST_DISABLED+x}" ]]; then
 		return $?
 	fi
 
 	# Get a new suggestion if the buffer is not empty after modification
-	if [ $#BUFFER -gt 0 ]; then
-		if [ -z "$ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE" -o $#BUFFER -le "$ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE" ]; then
+	if (( $#BUFFER > 0 )); then
+		if [[ -z "$ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE" ]] || (( $#BUFFER <= $ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE )); then
 			_zsh_autosuggest_fetch
 		fi
 	fi
@@ -380,7 +370,7 @@ _zsh_autosuggest_fetch() {
 _zsh_autosuggest_suggest() {
 	local suggestion="$1"
 
-	if [ -n "$suggestion" ] && [ $#BUFFER -gt 0 ]; then
+	if [[ -n "$suggestion" ]] && (( $#BUFFER )); then
 		POSTDISPLAY="${suggestion#$BUFFER}"
 	else
 		unset POSTDISPLAY
@@ -393,12 +383,12 @@ _zsh_autosuggest_accept() {
 
 	# When vicmd keymap is active, the cursor can't move all the way
 	# to the end of the buffer
-	if [ "$KEYMAP" = "vicmd" ]; then
+	if [[ "$KEYMAP" = "vicmd" ]]; then
 		max_cursor_pos=$((max_cursor_pos - 1))
 	fi
 
 	# Only accept if the cursor is at the end of the buffer
-	if [ $CURSOR -eq $max_cursor_pos ]; then
+	if [[ $CURSOR = $max_cursor_pos ]]; then
 		# Add the suggestion to the buffer
 		BUFFER="$BUFFER$POSTDISPLAY"
 
@@ -440,7 +430,7 @@ _zsh_autosuggest_partial_accept() {
 	retval=$?
 
 	# If we've moved past the end of the original buffer
-	if [ $CURSOR -gt $#original_buffer ]; then
+	if (( $CURSOR > $#original_buffer )); then
 		# Set POSTDISPLAY to text right of the cursor
 		POSTDISPLAY="$RBUFFER"
 
@@ -488,21 +478,11 @@ zle -N autosuggest-toggle _zsh_autosuggest_widget_toggle
 #
 
 _zsh_autosuggest_strategy_default() {
-	# Reset options to defaults and enable LOCAL_OPTIONS
-	emulate -L zsh
-
-	# Enable globbing flags so that we can use (#m)
-	setopt EXTENDED_GLOB
-
-	# Escape backslashes and all of the glob operators so we can use
-	# this string as a pattern to search the $history associative array.
-	# - (#m) globbing flag enables setting references for match data
-	local prefix="${1//(#m)[\\*?[\]<>()|^~#]/\\$MATCH}"
+	local prefix="$1"
 
 	# Get the history items that match
 	# - (r) subscript flag makes the pattern match on values
-	suggestion="${history[(r)$prefix*]}"
-
+	typeset -g suggestion="${history[(r)${(b)prefix}*]}"
 }
 
 #--------------------------------------------------------------------#
@@ -527,18 +507,18 @@ _zsh_autosuggest_strategy_default() {
 # `HIST_EXPIRE_DUPS_FIRST`.
 
 _zsh_autosuggest_strategy_match_prev_cmd() {
-	local prefix="${1//(#m)[\\()\[\]|*?~]/\\$MATCH}"
+	local prefix="$1"
 
 	# Get all history event numbers that correspond to history
 	# entries that match pattern $prefix*
 	local history_match_keys
-	history_match_keys=(${(k)history[(R)$prefix*]})
+	history_match_keys=(${(k)history[(R)${(b)prefix}*]})
 
 	# By default we use the first history number (most recent history entry)
 	local histkey="${history_match_keys[1]}"
 
 	# Get the previously executed command
-	local prev_cmd="$(_zsh_autosuggest_escape_command "${history[$((HISTCMD-1))]}")"
+	local prev_cmd="${history[$((HISTCMD-1))]}"
 
 	# Iterate up to the first 200 history event numbers that match $prefix
 	for key in "${(@)history_match_keys[1,200]}"; do
@@ -554,7 +534,7 @@ _zsh_autosuggest_strategy_match_prev_cmd() {
 	done
 
 	# Give back the matched history entry
-	suggestion="$history[$histkey]"
+	typeset -g suggestion="$history[$histkey]"
 }
 
 #--------------------------------------------------------------------#
@@ -621,7 +601,7 @@ _zsh_autosuggest_async_pty_create() {
 	typeset -h REPLY
 
 	# If we won't get a fd back from zpty, try to guess it
-	if [ $_ZSH_AUTOSUGGEST_ZPTY_RETURNS_FD -eq 0 ]; then
+	if (( ! $_ZSH_AUTOSUGGEST_ZPTY_RETURNS_FD )); then
 		integer -l zptyfd
 		exec {zptyfd}>&1  # Open a new file descriptor (above 10).
 		exec {zptyfd}>&-  # Close it so it's free to be used by zpty.
@@ -682,7 +662,7 @@ _zsh_autosuggest_start() {
 	# to the widget list variables to take effect on the next precmd.
 	add-zsh-hook precmd _zsh_autosuggest_bind_widgets
 
-	if [ -n "${ZSH_AUTOSUGGEST_USE_ASYNC+x}" ]; then
+	if [[ -n "${ZSH_AUTOSUGGEST_USE_ASYNC+x}" ]]; then
 		_zsh_autosuggest_async_start
 	fi
 }