diff --git a/security/keymint/support/include/remote_prov/remote_prov_utils.h b/security/keymint/support/include/remote_prov/remote_prov_utils.h
index 3b02fad..b8c69eb 100644
--- a/security/keymint/support/include/remote_prov/remote_prov_utils.h
+++ b/security/keymint/support/include/remote_prov/remote_prov_utils.h
@@ -17,6 +17,7 @@
 #pragma once
 
 #include <memory>
+#include <string>
 #include <vector>
 #include "aidl/android/hardware/security/keymint/IRemotelyProvisionedComponent.h"
 
@@ -129,8 +130,8 @@
  *     "name": <string>
  *   }
  */
-JsonOutput jsonEncodeCsrWithBuild(const std::string instance_name,
-                                  const cppbor::Array& csr, const std::string serialno_prop);
+JsonOutput jsonEncodeCsrWithBuild(const std::string& instance_name, const cppbor::Array& csr,
+                                  const std::string& serialno_prop);
 
 /**
  * Parses a DeviceInfo structure from the given CBOR data. The parsed data is then validated to
diff --git a/security/keymint/support/remote_prov_utils.cpp b/security/keymint/support/remote_prov_utils.cpp
index ecfdfd2..a830041 100644
--- a/security/keymint/support/remote_prov_utils.cpp
+++ b/security/keymint/support/remote_prov_utils.cpp
@@ -337,8 +337,8 @@
     return result;
 }
 
-JsonOutput jsonEncodeCsrWithBuild(const std::string instance_name, const cppbor::Array& csr,
-                                  const std::string serialno_prop) {
+JsonOutput jsonEncodeCsrWithBuild(const std::string& instance_name, const cppbor::Array& csr,
+                                  const std::string& serialno_prop) {
     const std::string kFingerprintProp = "ro.build.fingerprint";
 
     if (!::android::base::WaitForPropertyCreation(kFingerprintProp)) {