diff --git a/riscv-rt/CHANGELOG.md b/riscv-rt/CHANGELOG.md
index bb82c85d..4986a1f9 100644
--- a/riscv-rt/CHANGELOG.md
+++ b/riscv-rt/CHANGELOG.md
@@ -21,6 +21,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Fixed
 
+- Fix undefined behavior in heap initialization example documentation
 - Fix stack allocation algorithm for multi-core targets without M extension
 
 ## [v0.16.0] - 2025-09-08
diff --git a/riscv-rt/src/lib.rs b/riscv-rt/src/lib.rs
index 8760495e..1faf4284 100644
--- a/riscv-rt/src/lib.rs
+++ b/riscv-rt/src/lib.rs
@@ -279,7 +279,7 @@
 //! fn main() {
 //!     unsafe {
 //!         let heap_bottom = riscv_rt::heap_start() as usize;
-//!         let heap_size = &_heap_size as *const u8 as usize;
+//!         let heap_size = core::ptr::addr_of!(_heap_size) as usize;
 //!         some_allocator::initialize(heap_bottom, heap_size);
 //!     }
 //! }