diff --git a/lib/systems/default.nix b/lib/systems/default.nix
index 8eeab67f7f33..b45a5fd8d2ba 100644
--- a/lib/systems/default.nix
+++ b/lib/systems/default.nix
@@ -72,6 +72,13 @@ rec {
          release = null;
       };
 
+      kernelArch =
+        if final.isAarch32 then "arm"
+        else if final.isAarch64 then "arm64"
+        else if final.isx86_32 then "x86"
+        else if final.isx86_64 then "ia64"
+        else final.parsed.cpu.name;
+
       qemuArch =
         if final.isArm then "arm"
         else if final.isx86_64 then "x86_64"
diff --git a/pkgs/os-specific/linux/kernel-headers/default.nix b/pkgs/os-specific/linux/kernel-headers/default.nix
index c00fc1761d59..ea4e041d43a0 100644
--- a/pkgs/os-specific/linux/kernel-headers/default.nix
+++ b/pkgs/os-specific/linux/kernel-headers/default.nix
@@ -12,7 +12,7 @@ let
       inherit sha256;
     };
 
-    ARCH = stdenvNoCC.hostPlatform.platform.kernelArch or (throw "missing kernelArch");
+    ARCH = stdenvNoCC.hostPlatform.platform.kernelArch or stdenvNoCC.hostPlatform.kernelArch;
 
     # It may look odd that we use `stdenvNoCC`, and yet explicit depend on a cc.
     # We do this so we have a build->build, not build->host, C compiler.