diff --git a/sim/firesim-lib/src/main/cc/fesvr/firesim_tsi.h b/sim/firesim-lib/src/main/cc/fesvr/firesim_tsi.h
index b6298fb311..82be9deb38 100644
--- a/sim/firesim-lib/src/main/cc/fesvr/firesim_tsi.h
+++ b/sim/firesim-lib/src/main/cc/fesvr/firesim_tsi.h
@@ -34,6 +34,11 @@ class firesim_tsi_t final : public testchip_tsi_t {
   void load_mem_write(addr_t addr, size_t nbytes, const void *src) override;
   void load_mem_read(addr_t addr, size_t nbytes, void *dst) override;
 
+  // This must be exactly the same as hKey.dataBits in the LoadMem widget
+  // See discussion here: https://github.com/firesim/firesim/pull/1401
+  // TODO: Avoid hardcoding this value here
+  size_t chunk_align() override { return 8; }
+
   std::deque<firesim_loadmem_t> loadmem_write_reqs;
   std::deque<firesim_loadmem_t> loadmem_read_reqs;
   std::deque<char> loadmem_write_data;