diff --git a/e2e/src/test/scala/scalapb/StructUtilsSpec.scala b/e2e/src/test/scala/scalapb/StructUtilsSpec.scala
index 7930e4f0c..6d68d6559 100644
--- a/e2e/src/test/scala/scalapb/StructUtilsSpec.scala
+++ b/e2e/src/test/scala/scalapb/StructUtilsSpec.scala
@@ -78,7 +78,7 @@ class StructUtilsSpec extends AnyFlatSpec with Matchers with EitherValues {
       Struct(
         Map(
           "optional_bytes" -> Value(
-            Value.Kind.StringValue(new String(Base64.getEncoder.encode(someBytesValue.toByteArray)))
+            Value.Kind.StringValue(new String(Base64.getEncoder.encode(someBytesValue.toByteArray())))
           )
         )
       )
@@ -213,7 +213,7 @@ class StructUtilsSpec extends AnyFlatSpec with Matchers with EitherValues {
           Map(
             "optional_bytes" -> Value(
               Value.Kind.StringValue(
-                new String(Base64.getEncoder.encode(someBytesValue.toByteArray))
+                new String(Base64.getEncoder.encode(someBytesValue.toByteArray()))
               )
             )
           )