diff --git a/modules/services/ssh-agent.nix b/modules/services/ssh-agent.nix
index 88ecf38b8..d2c170c21 100644
--- a/modules/services/ssh-agent.nix
+++ b/modules/services/ssh-agent.nix
@@ -20,7 +20,7 @@ in {
     ];
 
     home.sessionVariablesExtra = ''
-      if [[ -z "$SSH_AUTH_SOCK" ]]; then
+      if [ -z "$SSH_AUTH_SOCK" ]; then
         export SSH_AUTH_SOCK=$XDG_RUNTIME_DIR/ssh-agent
       fi
     '';