diff --git a/libqpdf/QPDF_encryption.cc b/libqpdf/QPDF_encryption.cc
index 8be325a..33282a2 100644
--- a/libqpdf/QPDF_encryption.cc
+++ b/libqpdf/QPDF_encryption.cc
@@ -600,18 +600,17 @@ QPDF::EncryptionData::recover_encryption_key_with_password(
 }
 
 QPDF::encryption_method_e
-QPDF::EncryptionParameters::interpretCF(QPDFObjectHandle const& cf) const
+QPDF::EncryptionParameters::interpretCF(Name const& cf) const
 {
-    if (!cf.isName()) {
+    if (!cf) {
         // Default: /Identity
         return e_none;
     }
-    std::string filter = cf.getName();
-    auto it = crypt_filters.find(filter);
+    auto it = crypt_filters.find(cf);
     if (it != crypt_filters.end()) {
         return it->second;
     }
-    if (filter == "/Identity") {
+    if (cf == "/Identity") {
         return e_none;
     }
     return e_unknown;
diff --git a/libqpdf/qpdf/QPDF_private.hh b/libqpdf/qpdf/QPDF_private.hh
index cd51ec2..19d9e3c 100644
--- a/libqpdf/qpdf/QPDF_private.hh
+++ b/libqpdf/qpdf/QPDF_private.hh
@@ -7,6 +7,8 @@
 #include <qpdf/QPDFObject_private.hh>
 #include <qpdf/QPDFTokenizer_private.hh>
 
+using namespace qpdf;
+
 // Writer class is restricted to QPDFWriter so that only it can call certain methods.
 class QPDF::Writer
 {
@@ -204,7 +206,7 @@ class QPDF::EncryptionParameters
     }
 
     void initialize(QPDF& qpdf);
-    encryption_method_e interpretCF(QPDFObjectHandle const& cf) const;
+    encryption_method_e interpretCF(Name const& cf) const;
 
   private:
     bool encrypted{false};