diff --git a/README.md b/README.md
index ae9ab53..3cfd2e8 100644
--- a/README.md
+++ b/README.md
@@ -79,9 +79,11 @@ Widgets that modify the buffer and are not found in any of these arrays will fet
 Set `ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE` to an integer value to disable autosuggestion for large buffers. The default is unset, which means that autosuggestion will be tried for any buffer size. Recommended value is 20.
 This can be useful when pasting large amount of text in the terminal, to avoid triggering autosuggestion for strings that are too long.
 
-### Enable Asynchronous Mode
+### Asynchronous Mode
 
-As of `v0.4.0`, suggestions can be fetched asynchronously. To enable this behavior, set the `ZSH_AUTOSUGGEST_USE_ASYNC` variable (it can be set to anything).
+Suggestions are fetched asynchronously by default in zsh versions 5.0.8 and greater. To disable asynchronous suggestions and fetch them synchronously instead, `unset ZSH_AUTOSUGGEST_USE_ASYNC` after sourcing the plugin.
+
+Alternatively, if you are using a version of zsh older than 5.0.8 and want to enable asynchronous mode, set the `ZSH_AUTOSUGGEST_USE_ASYNC` variable after sourcing the plugin (it can be set to anything). Note that there is [a bug](https://github.com/zsh-users/zsh-autosuggestions/issues/364#issuecomment-481423232) in versions of zsh older than 5.0.8 where <kbd>ctrl</kbd> + <kbd>c</kbd> will fail to reset the prompt immediately after fetching a suggestion asynchronously.
 
 ### Disabling automatic widget re-binding
 
diff --git a/spec/options/use_async_spec.rb b/spec/options/use_async_spec.rb
deleted file mode 100644
index 420dcc3..0000000
--- a/spec/options/use_async_spec.rb
+++ /dev/null
@@ -1,7 +0,0 @@
-describe 'suggestion fetching' do
-  it 'is performed synchronously'
-
-  context 'when ZSH_AUTOSUGGEST_USE_ASYNC is set' do
-    it 'is performed asynchronously'
-  end
-end
diff --git a/src/start.zsh b/src/start.zsh
index 5991039..5d4ee52 100644
--- a/src/start.zsh
+++ b/src/start.zsh
@@ -18,6 +18,16 @@ _zsh_autosuggest_start() {
 	_zsh_autosuggest_bind_widgets
 }
 
+# Mark for auto-loading the functions that we use
+autoload -Uz add-zsh-hook is-at-least
+
+# Automatically enable asynchronous mode in newer versions of zsh. Disable for
+# older versions because there is a bug when using async mode where ^C does not
+# work immediately after fetching a suggestion.
+# See https://github.com/zsh-users/zsh-autosuggestions/issues/364
+if is-at-least 5.0.8; then
+	typeset -g ZSH_AUTOSUGGEST_USE_ASYNC=
+fi
+
 # Start the autosuggestion widgets on the next precmd
-autoload -Uz add-zsh-hook
 add-zsh-hook precmd _zsh_autosuggest_start
diff --git a/src/strategies/completion.zsh b/src/strategies/completion.zsh
index 4290f0c..e2d114c 100644
--- a/src/strategies/completion.zsh
+++ b/src/strategies/completion.zsh
@@ -45,8 +45,6 @@ _zsh_autosuggest_capture_completion_widget() {
 zle -N autosuggest-capture-completion _zsh_autosuggest_capture_completion_widget
 
 _zsh_autosuggest_capture_setup() {
-	autoload -Uz is-at-least
-
 	# There is a bug in zpty module in older zsh versions by which a
 	# zpty that exits will kill all zpty processes that were forked
 	# before it. Here we set up a zsh exit hook to SIGKILL the zpty
diff --git a/zsh-autosuggestions.zsh b/zsh-autosuggestions.zsh
index 8aa8591..ee9d800 100644
--- a/zsh-autosuggestions.zsh
+++ b/zsh-autosuggestions.zsh
@@ -549,8 +549,6 @@ _zsh_autosuggest_capture_completion_widget() {
 zle -N autosuggest-capture-completion _zsh_autosuggest_capture_completion_widget
 
 _zsh_autosuggest_capture_setup() {
-	autoload -Uz is-at-least
-
 	# There is a bug in zpty module in older zsh versions by which a
 	# zpty that exits will kill all zpty processes that were forked
 	# before it. Here we set up a zsh exit hook to SIGKILL the zpty
@@ -861,6 +859,16 @@ _zsh_autosuggest_start() {
 	_zsh_autosuggest_bind_widgets
 }
 
+# Mark for auto-loading the functions that we use
+autoload -Uz add-zsh-hook is-at-least
+
+# Automatically enable asynchronous mode in newer versions of zsh. Disable for
+# older versions because there is a bug when using async mode where ^C does not
+# work immediately after fetching a suggestion.
+# See https://github.com/zsh-users/zsh-autosuggestions/issues/364
+if is-at-least 5.0.8; then
+	typeset -g ZSH_AUTOSUGGEST_USE_ASYNC=
+fi
+
 # Start the autosuggestion widgets on the next precmd
-autoload -Uz add-zsh-hook
 add-zsh-hook precmd _zsh_autosuggest_start