diff --git a/src/setup.zsh b/src/setup.zsh
index c74489f..4999aad 100644
--- a/src/setup.zsh
+++ b/src/setup.zsh
@@ -7,4 +7,4 @@
 autoload -Uz add-zsh-hook
 
 # Asynchronous suggestions are generated in a pty
-zmodload zsh/zpty
+zmodload zsh/zpty 2> /dev/null || zpty() { return 1 }
diff --git a/zsh-autosuggestions.zsh b/zsh-autosuggestions.zsh
index ccfe07e..b0d19e0 100644
--- a/zsh-autosuggestions.zsh
+++ b/zsh-autosuggestions.zsh
@@ -33,7 +33,7 @@
 autoload -Uz add-zsh-hook
 
 # Asynchronous suggestions are generated in a pty
-zmodload zsh/zpty
+zmodload zsh/zpty 2> /dev/null || zpty() { return 1 }
 
 #--------------------------------------------------------------------#
 # Global Configuration Variables                                     #