diff --git a/.gitignore b/.gitignore
index 8b0b664..f495d40 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,8 @@
 # isnt' parsed by the GitHub Action:
 /deno.lock
 
+# NPM (for AJV):
+/node_modules
+/package-lock.json
+/package.json
+
diff --git a/test.sh b/test.sh
index 134b7cf..41c17c9 100755
--- a/test.sh
+++ b/test.sh
@@ -2,7 +2,14 @@
 
 deno task run-tests
 
+# install AJV:
+npm init -y
+npm install ajv
+npm install ajv-cli
+npm install ajv-formats
+
+# validate schema using AJV:
 TS_LIONCORE_M3_SCHEMA=../repos/lionweb-typescript/packages/artifacts/schemas/lioncore_m3.serialization.schema.json
 JAVA_LIONCORE_SERIALIZATION=../repos/lionweb-java/core/src/test/resources/serialization/lioncore.json
-npx ajv -c ajv-formats --spec=draft2020 --strict=true --allErrors=true --allowUnionTypes=true test -s $TS_LIONCORE_M3_SCHEMA -d $JAVA_LIONCORE_SERIALIZATION --valid
+./node_modules/.bin/ajv -c ajv-formats --spec=draft2020 --strict=true --allErrors=true --allowUnionTypes=true test -s $TS_LIONCORE_M3_SCHEMA -d $JAVA_LIONCORE_SERIALIZATION --valid