diff --git a/spec/async_spec.rb b/spec/async_spec.rb
index 10f1a74..152adde 100644
--- a/spec/async_spec.rb
+++ b/spec/async_spec.rb
@@ -1,4 +1,8 @@
 context 'with asynchronous suggestions enabled' do
+  before do
+    skip 'Async mode not supported below v5.0.8' if session.zsh_version < Gem::Version.new('5.0.8')
+  end
+
   let(:options) { ["ZSH_AUTOSUGGEST_USE_ASYNC="] }
 
   describe '`up-line-or-beginning-search`' do
diff --git a/spec/terminal_session.rb b/spec/terminal_session.rb
index 2d9468f..f91ee6c 100644
--- a/spec/terminal_session.rb
+++ b/spec/terminal_session.rb
@@ -18,6 +18,10 @@ class TerminalSession
     tmux_command("new-session -d -x #{opts[:width]} -y #{opts[:height]} '#{cmd}'")
   end
 
+  def zsh_version
+    @zsh_version ||= Gem::Version.new(`#{ZSH_BIN} -c 'echo -n $ZSH_VERSION'`)
+  end
+
   def tmux_socket_name
     @tmux_socket_name ||= SecureRandom.hex(6)
   end