diff --git a/pkgs/development/tools/tradcpp/aarch64.patch b/pkgs/development/tools/tradcpp/aarch64.patch
new file mode 100644
index 000000000000..ef7ad9828ace
--- /dev/null
+++ b/pkgs/development/tools/tradcpp/aarch64.patch
@@ -0,0 +1,12 @@
+diff a/config.h b/config.h
+--- a/config.h
++++ b/config.h
+@@ -124,6 +124,8 @@
+ #define CONFIG_CPU "__ppc64__"
+ #elif defined(__ARM__)
+ #define CONFIG_CPU "__ARM__"
++#elif defined(__aarch64__)
++#define CONFIG_CPU "__aarch64__"
+ #else
+ /* let it go */
+ #endif
diff --git a/pkgs/development/tools/tradcpp/default.nix b/pkgs/development/tools/tradcpp/default.nix
index 64a97ad00873..7f395174bb41 100644
--- a/pkgs/development/tools/tradcpp/default.nix
+++ b/pkgs/development/tools/tradcpp/default.nix
@@ -11,7 +11,10 @@ stdenv.mkDerivation {
   # tradcpp only comes with BSD-make Makefile; the patch adds configure support
   buildInputs = [ autoconf ];
   preConfigure = "autoconf";
-  patches = [ ./tradcpp-configure.patch ];
+  patches = [
+    ./tradcpp-configure.patch
+    ./aarch64.patch
+  ];
 
   meta = with stdenv.lib; {
     description = "A traditional (K&R-style) C macro preprocessor";