diff --git a/changes/bug24424 b/changes/bug24424
new file mode 100644
index 000000000..63c2d39ba
--- /dev/null
+++ b/changes/bug24424
@@ -0,0 +1,3 @@
+  o Minor features (portability):
+    - Tor now compiles correctly on arm64 with libseccomp-dev installed.
+      (It doesn't yet work with the sandbox enabled.) Closes ticket 24424.
diff --git a/src/common/sandbox.c b/src/common/sandbox.c
index ba6c3efb9..8827370c2 100644
--- a/src/common/sandbox.c
+++ b/src/common/sandbox.c
@@ -106,6 +106,11 @@
 
 #define M_SYSCALL arm_r7
 
+#elif defined(__aarch64__) && defined(__LP64__)
+
+#define REG_SYSCALL 8
+#define M_SYSCALL regs[REG_SYSCALL]
+
 #endif /* defined(__i386__) || ... */
 
 /**Determines if at least one sandbox is active.*/