diff --git a/src/lib_klee_replay.rs b/src/lib_klee_replay.rs
index 301b65dec9bf0bd58e66e4491a70a2be3e42fa9d..50b92d74cff0ad58a36dfa1013728e936a96db78 100644
--- a/src/lib_klee_replay.rs
+++ b/src/lib_klee_replay.rs
@@ -10,7 +10,7 @@ pub fn klee_assume(_cond: bool) {}
 pub fn klee_make_symbolic<T>(t: &mut T) {
     // force LLVM to consider data to be mutated
     unsafe {
-        core::arch::asm!("bkpt #2", in(r0) t)
+        core::arch::asm!("bkpt #2", in(a[1]) t)
     }
     // unsafe {
     //     llvm_asm!("bkpt #0" : /* output */: /* input */ "r"(t): /* clobber */ : "volatile")