diff --git a/nixos/modules/system/boot/loader/systemd-boot/systemd-boot.nix b/nixos/modules/system/boot/loader/systemd-boot/systemd-boot.nix
index cee8663f0040..e73048dc2ecb 100644
--- a/nixos/modules/system/boot/loader/systemd-boot/systemd-boot.nix
+++ b/nixos/modules/system/boot/loader/systemd-boot/systemd-boot.nix
@@ -323,15 +323,15 @@ in {
     assertions = [
       {
         assertion = (hasPrefix "/" efi.efiSysMountPoint);
-        message = "The ESP mount point '${efi.efiSysMountPoint}' must be an absolute path";
+        message = "The ESP mount point '${toString efi.efiSysMountPoint}' must be an absolute path";
       }
       {
         assertion = cfg.xbootldrMountPoint == null || (hasPrefix "/" cfg.xbootldrMountPoint);
-        message = "The XBOOTLDR mount point '${cfg.xbootldrMountPoint}' must be an absolute path";
+        message = "The XBOOTLDR mount point '${toString cfg.xbootldrMountPoint}' must be an absolute path";
       }
       {
         assertion = cfg.xbootldrMountPoint != efi.efiSysMountPoint;
-        message = "The XBOOTLDR mount point '${cfg.xbootldrMountPoint}' cannot be the same as the ESP mount point '${efi.efiSysMountPoint}'";
+        message = "The XBOOTLDR mount point '${toString cfg.xbootldrMountPoint}' cannot be the same as the ESP mount point '${toString efi.efiSysMountPoint}'";
       }
       {
         assertion = (config.boot.kernelPackages.kernel.features or { efiBootStub = true; }) ? efiBootStub;