diff --git a/pkgs/os-specific/linux/kernel/manual-config.nix b/pkgs/os-specific/linux/kernel/manual-config.nix
index f922116ed36b..b0735e94619d 100644
--- a/pkgs/os-specific/linux/kernel/manual-config.nix
+++ b/pkgs/os-specific/linux/kernel/manual-config.nix
@@ -110,7 +110,7 @@ let
         make $makeFlags prepare
         actualModDirVersion="$(cat $buildRoot/include/config/kernel.release)"
         if [ "$actualModDirVersion" != "${modDirVersion}" ]; then
-          echo "Error: modDirVersion specified in the Nix expression is wrong, it should be: $actualModDirVersion"
+          echo "Error: modDirVersion ${modDirVersion} specified in the Nix expression is wrong, it should be: $actualModDirVersion"
           exit 1
         fi