diff --git a/index.js b/index.js
index 037ed58..86dd4d0 100644
--- a/index.js
+++ b/index.js
@@ -24,7 +24,7 @@ const LEVEL_MAP = {
 function getTransformStream(options = {}) {
   const formattingEnabled = options.logFormat !== "json";
 
-  const levelAsString = options.logLevelInString === "true";
+  const levelAsString = options.logLevelInString;
   const sentryEnabled = !!options.sentryDsn;
 
   if (sentryEnabled) {
diff --git a/test/index.test.js b/test/index.test.js
index f702eed..dd9cdac 100644
--- a/test/index.test.js
+++ b/test/index.test.js
@@ -143,6 +143,7 @@ test("API", (t) => {
 
       const transform = getTransformStream({
         logFormat: "json",
+        logLevelInString: true,
       });
       transform.pipe(streamLogsToOutput);
       const log = pino({}, transform);
@@ -155,6 +156,8 @@ test("API", (t) => {
         'No "\\n" is added to end of line'
       );
 
+      t.equal(JSON.parse(output).level, "info");
+
       t.end();
     }
   );