diff --git a/connections/implementation/mediums/advertisements/advertisement_util.cc b/connections/implementation/mediums/advertisements/advertisement_util.cc
index a0f77069..c85a07ca 100644
--- a/connections/implementation/mediums/advertisements/advertisement_util.cc
+++ b/connections/implementation/mediums/advertisements/advertisement_util.cc
@@ -24,9 +24,10 @@
 
 namespace nearby::connections::advertisements {
 namespace {
+constexpr uint8_t kFakeEncryptionSize = 16;
 constexpr absl::string_view kFakeEncryptionKey =
     "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f";
-}
+}  // namespace
 
 // Should always match the protocol implementation to read device name.
 // LINT.IfChange
@@ -70,7 +71,7 @@ std::string BuildEndpointInfo(const std::string& device_name) {
   // VERSION | HAS_DEVICE_NAME | DEVICE_TYPE
   endpoint_info.push_back(0x22);
   // salt and encrypted_metadata_key
-  endpoint_info.append(kFakeEncryptionKey.data(), kFakeEncryptionKey.size());
+  endpoint_info.append(kFakeEncryptionKey.data(), kFakeEncryptionSize);
   endpoint_info.push_back(device_name.size());
   endpoint_info.append(device_name);
   return endpoint_info;
diff --git a/connections/implementation/mediums/advertisements/advertisement_util_test.cc b/connections/implementation/mediums/advertisements/advertisement_util_test.cc
index 5916417d..76d58aa1 100644
--- a/connections/implementation/mediums/advertisements/advertisement_util_test.cc
+++ b/connections/implementation/mediums/advertisements/advertisement_util_test.cc
@@ -49,5 +49,11 @@ TEST(AdvertisementUtilTest, ReadInvaidDeviceName) {
           .has_value());
 }
 
+TEST(AdvertisementUtilTest, BuildEndpointInfo) {
+  std::string device_name = "Test_device";
+  std::string endpoint_info = BuildEndpointInfo(device_name);
+  EXPECT_EQ(ReadDeviceName(ByteArray(endpoint_info)), device_name);
+}
+
 }  // namespace
 }  // namespace nearby::connections::advertisements