diff --git a/modules/ecash-lib/build-and-check-wasm.sh b/modules/ecash-lib/build-and-check-wasm.sh
new file mode 100755
--- /dev/null
+++ b/modules/ecash-lib/build-and-check-wasm.sh
@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+export LC_ALL=C.UTF-8
+
+pushd "../ecash-lib-wasm"
+./dockerbuild.sh
+echo "55bc25a70a1ef5e76720593295b0e68cebc54dd1c0ade5124f2c11fa1346b08f target/wasm32-unknown-unknown/release-wasm/ecash_lib_wasm.wasm" | sha256sum -c
+popd
\ No newline at end of file
diff --git a/modules/ecash-lib/package.json b/modules/ecash-lib/package.json
--- a/modules/ecash-lib/package.json
+++ b/modules/ecash-lib/package.json
@@ -6,6 +6,7 @@
     "type": "module",
     "scripts": {
         "build": "tsc && cp -r ./src/ffi ./dist",
+        "prebuild": "./build-and-check-wasm.sh",
         "test": "mocha --import=tsx ./src/*.test.ts ./src/**/*.test.ts",
         "integration-tests": "mocha --import=tsx ./tests/*.test.ts --timeout 60000",
         "coverage": "nyc npm run test",