diff --git a/flake.nix b/flake.nix
index 0dd0b9655..b3bcd07c9 100644
--- a/flake.nix
+++ b/flake.nix
@@ -62,4 +62,9 @@
 
       # Our supported systems are the same supported systems as the Zig binaries.
     }) (builtins.attrNames zig.packages));
+
+  nixConfig = {
+    extra-substituters = ["https://ghostty.cachix.org"];
+    extra-trusted-public-keys = ["ghostty.cachix.org-1:QB389yTa6gTyneehvqG58y0WnHjQOqgnA+wBnpWWxns="];
+  };
 }
diff --git a/src/config/Config.zig b/src/config/Config.zig
index eb63f37ca..5b816c676 100644
--- a/src/config/Config.zig
+++ b/src/config/Config.zig
@@ -2312,7 +2312,7 @@ pub const RepeatablePath = struct {
             // If it isn't absolute, we need to make it absolute relative
             // to the base.
             var buf: [std.fs.MAX_PATH_BYTES]u8 = undefined;
-            const abs = std.os.realpath(path, &buf) catch |err| {
+            const abs = dir.realpath(path, &buf) catch |err| {
                 try errors.add(alloc, .{
                     .message = try std.fmt.allocPrintZ(
                         alloc,