diff --git a/pkgs/os-specific/linux/kernel/manual-config.nix b/pkgs/os-specific/linux/kernel/manual-config.nix
index 6805355052a4..47f5c034c74d 100644
--- a/pkgs/os-specific/linux/kernel/manual-config.nix
+++ b/pkgs/os-specific/linux/kernel/manual-config.nix
@@ -102,7 +102,11 @@ let
         runHook postConfigure
       '';
 
-      buildFlags = [ "KBUILD_BUILD_VERSION=1-NixOS" platform.kernelTarget ] ++ optional isModular "modules";
+      buildFlags = [
+        "KBUILD_BUILD_VERSION=1-NixOS"
+        "KBUILD_BUILD_TIMESTAMP=Thu_Jan__1_00:00:01_UTC_1970"
+	platform.kernelTarget
+      ] ++ optional isModular "modules";
 
       installFlags = [
         "INSTALLKERNEL=${installkernel}"