diff --git a/CHANGELOG.md b/CHANGELOG.md
index 87f32293..beb58c3b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,6 +25,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ### Infrastructure
 
+- Added a `Makefile` with a `build-docker` target utilizing the `stellar/rs-soroban-sdk` image to guarantee WASM binary reproducibility, allowing anyone to verify that the deployed on-chain bytecode matches the source (#533).
 - Resolved pre-existing CI debt surfaced by the `fmt` and `clippy` gates added in #403: test fixture missing bindings restored in `src/test.rs` and `src/tests/test_init.rs`, `result` double-move fixed in `src/tests/test_admin.rs`, `cargo fmt --all` drift cleared across `src/issues_test.rs` and `src/lib.rs`, and clippy lints addressed (`manual_div_ceil` in `src/lib.rs`; `dead_code` suppressed on deferred storage helpers pending the DataKey audit in #409). All three CI jobs (`test`, `fmt`, `clippy`) now exit 0 on a clean checkout (#418).
 
 ### Refactored
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a3772c82..d8ed6ea5 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -43,8 +43,11 @@ git remote add upstream https://github.com/Iris-IV/ProofOfHeart-stellar.git
 > **Heads up:** The first `cargo build` downloads and compiles all Rust dependencies. This can take **10–20 minutes** and use **1–2 GB** of disk space. Subsequent builds are much faster.
 
 ```bash
-# Build WASM
-cargo build --target wasm32-unknown-unknown --release
+# Build WASM (Local development)
+stellar contract build
+
+# Build reproducible WASM (Required for production deployment)
+make build-docker
 
 # Run tests
 cargo test --features testutils
@@ -60,7 +63,7 @@ CI runs these checks on every PR. Run locally before pushing:
 cargo fmt --check
 cargo clippy --all-targets --features testutils -- -D warnings
 cargo test --features testutils
-cargo build --target wasm32-unknown-unknown --release
+stellar contract build
 ```
 
 All four must pass.
diff --git a/Makefile b/Makefile
new file mode 100644
index 00000000..26f1887a
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,18 @@
+default: build
+
+all: test
+
+build:
+	stellar contract build
+
+build-docker:
+	docker run --rm -v $(PWD):/workspace -w /workspace stellar/rs-soroban-sdk:20.1.0 stellar contract build
+
+test:
+	cargo test --features testutils
+
+fmt:
+	cargo fmt --all
+
+clean:
+	cargo clean
diff --git a/README.md b/README.md
index a1f14c2b..03fc7bdf 100644
--- a/README.md
+++ b/README.md
@@ -139,8 +139,11 @@ This repository contains the **Soroban smart contract** that powers the on-chain
 git clone https://github.com/Iris-IV/ProofOfHeart-stellar.git
 cd ProofOfHeart-stellar
 
-# Build the contract
-cargo build --target wasm32-unknown-unknown --release
+# Build the contract for local development
+stellar contract build
+
+# Build a deterministic, reproducible WASM binary for deployment/verification
+make build-docker
 ```
 
 ### Test