diff --git a/security/nss/lib/mozpkix/lib/pkixnss.cpp b/security/nss/lib/mozpkix/lib/pkixnss.cpp
index 31aa1ddd67..6eb367eae4 100644
--- a/security/nss/lib/mozpkix/lib/pkixnss.cpp
+++ b/security/nss/lib/mozpkix/lib/pkixnss.cpp
@@ -323,13 +323,21 @@ VerifyMLDSASignedDataNSS(Input data,
   SECItem dataItem(UnsafeMapInputToSECItem(data));
   CK_MECHANISM_TYPE mechanism;
 
-  switch (pubk->u.mldsa.paramSet) {
-    case SEC_OID_ML_DSA_44:
-    case SEC_OID_ML_DSA_65:
-    case SEC_OID_ML_DSA_87:
+  switch (SEC_GetSignatureAlgorithmOidTag(pubk->keyType, pubk->u.mldsa.params)) {
+    case CKP_ML_DSA_44:
+      hashPolicyTag = SEC_OID_UNKNOWN;
+      mechanism = CKM_ML_DSA;
+      signaturePolicyTag = SEC_OID_PRIVATE_3;
+      break;
+    case CKP_ML_DSA_65:
+      hashPolicyTag = SEC_OID_UNKNOWN;
       mechanism = CKM_ML_DSA;
-      signaturePolicyTag = pubk->u.mldsa.paramSet;
+      signaturePolicyTag = SEC_OID_PRIVATE_4;
+      break;
+    case CKP_ML_DSA_87:
       hashPolicyTag = SEC_OID_UNKNOWN;
+      mechanism = CKM_ML_DSA;
+      signaturePolicyTag = SEC_OID_PRIVATE_5;
       break;
     default:
       return Result::ERROR_UNSUPPORTED_KEYALG;