diff --git a/home-manager/install.nix b/home-manager/install.nix
index c58c0ba7..bafb9a06 100644
--- a/home-manager/install.nix
+++ b/home-manager/install.nix
@@ -21,6 +21,16 @@ runCommand
       {
         # Let Home Manager install and manage itself.
         programs.home-manager.enable = true;
+
+        # This value determines the Home Manager release that your
+        # configuration is compatible with. This helps avoid breakage
+        # when a new Home Manager release introduces backwards
+        # incompatible changes.
+        #
+        # You can update Home Manager without changing this value. See
+        # the Home Manager release notes for a list of state version
+        # changes in each release.
+        home.stateVersion = "19.09";
       }
       EOF
       fi