diff --git a/src/security/sec-policy-self-verify.cpp b/src/security/sec-policy-self-verify.cpp
index 2793b69..6f7b657 100644
--- a/src/security/sec-policy-self-verify.cpp
+++ b/src/security/sec-policy-self-verify.cpp
@@ -22,7 +22,7 @@
 
 ptr_lib::shared_ptr<ValidationRequest>
 SecPolicySelfVerify::checkVerificationPolicy
-  (const ptr_lib::shared_ptr<Data>& data, int stepCount, const OnVerified& onVerified, const OnVerifyFailed& onVerifyFailed)
+  (const ptr_lib::shared_ptr<const Data>& data, int stepCount, const OnVerified& onVerified, const OnVerifyFailed& onVerifyFailed)
 { 
   // Cast to const Data* so that we use the const version of getSignature() and don't reset the default encoding.
   const Sha256WithRsaSignature *signature = dynamic_cast<const Sha256WithRsaSignature*>(((const Data*)data.get())->getSignature());