diff --git a/index.js b/index.js
index eca4ee6..cd895dc 100644
--- a/index.js
+++ b/index.js
@@ -92,4 +92,15 @@ export const onPreBuild = async ({
   console.log(`  Done.`);
 };
 
-export const onPreDev = onPreBuild;
+export const onPreDev = async ({ inputs, netlifyConfig, utils, constants }) => {
+  if (!process.env.RUN_NETLIFY_CSP_NONCE_PLUGIN_TESTS) {
+    return;
+  }
+
+  return onPreBuild({
+    inputs,
+    netlifyConfig,
+    utils,
+    constants,
+  });
+};
diff --git a/tests/integration/helpers.ts b/tests/integration/helpers.ts
index 50f55a0..01cc76e 100644
--- a/tests/integration/helpers.ts
+++ b/tests/integration/helpers.ts
@@ -30,6 +30,7 @@ export const serve = async ({
   const proc = execa(...command(port), {
     all: true,
     cancelSignal: abortController.signal,
+    env: { RUN_NETLIFY_CSP_NONCE_PLUGIN_TESTS: "1" },
   });
 
   await new Promise<void>((resolve) => {