diff --git a/lib/prawn/security.rb b/lib/prawn/security.rb
index f9902fe13..1070b075d 100644
--- a/lib/prawn/security.rb
+++ b/lib/prawn/security.rb
@@ -209,7 +209,7 @@ module PDF
   module Core
     module_function
 
-    # Like PdfObject, but returns an encrypted result if required.
+    # Like pdf_object, but returns an encrypted result if required.
     # For direct objects, requires the object identifier and generation number
     # from the indirect object referencing obj.
     #
@@ -232,7 +232,7 @@ def encrypted_pdf_object(obj, key, id, gen, in_content_stream = false)
         ).gsub(/[\\\n\(\)]/) { |m| "\\#{m}" }
         "(#{obj})"
       when String
-        PdfObject(
+        pdf_object(
           ByteString.new(
             Prawn::Document::Security.encrypt_string(obj, key, id, gen)
           ),
@@ -245,17 +245,17 @@ def encrypted_pdf_object(obj, key, id, gen, in_content_stream = false)
             raise PDF::Core::Errors::FailedObjectConversion,
               'A PDF Dictionary must be keyed by names'
           end
-          output << PdfObject(k.to_sym, in_content_stream) << ' ' <<
+          output << pdf_object(k.to_sym, in_content_stream) << ' ' <<
             encrypted_pdf_object(v, key, id, gen, in_content_stream) << "\n"
         end
         output << '>>'
       when NameTree::Value
-        PdfObject(obj.name) + ' ' +
+        pdf_object(obj.name) + ' ' +
           encrypted_pdf_object(obj.value, key, id, gen, in_content_stream)
       when PDF::Core::OutlineRoot, PDF::Core::OutlineItem
         encrypted_pdf_object(obj.to_hash, key, id, gen, in_content_stream)
-      else # delegate back to PdfObject
-        PdfObject(obj, in_content_stream)
+      else # delegate back to pdf_object
+        pdf_object(obj, in_content_stream)
       end
     end
 
diff --git a/prawn.gemspec b/prawn.gemspec
index 241d7051a..1b5f88248 100644
--- a/prawn.gemspec
+++ b/prawn.gemspec
@@ -35,7 +35,7 @@ Gem::Specification.new do |spec|
   spec.licenses = %w[PRAWN GPL-2.0 GPL-3.0]
 
   spec.add_dependency('ttfunk', '~> 1.5')
-  spec.add_dependency('pdf-core', '~> 0.6.1')
+  spec.add_dependency('pdf-core', '~> 0.7.0')
 
   spec.add_development_dependency('pdf-inspector', '~> 1.2.1')
   spec.add_development_dependency('yard')
diff --git a/spec/manual_spec.rb b/spec/manual_spec.rb
index 042375b1c..3245e2db3 100644
--- a/spec/manual_spec.rb
+++ b/spec/manual_spec.rb
@@ -5,9 +5,9 @@
 MANUAL_HASH =
   case RUBY_ENGINE
   when 'ruby'
-    'b213efa532c7f2a159f69ee5559efe95333810e302ea09f60772ffdea6bb74eb477d6e7411454ba58376cf75e17bc6f7181eee991ac5d7d0c0bac71c9892a41c'
+    'b55f154c9093c60f38051c75920c8157c775b946b0c77ffafc0a8a634ad5401e8ceafd0b96942839f82bacd726a690af3fdd1fd9e185616f67c6c0edfcfd0460'
   when 'jruby'
-    '0d65981e685d44c83d4ed1b0c7266da0d2b2d7c749d5d332b6837a29d44a808d03ee2ed09a9a6cf9105cf90f8a6af44dad4a5f152e6a11b05561a74ddf54b643'
+    'd2eb71ea3ddc35acb185de671a6fa48862ebad5727ce372e3a742f45d31447765c4004fbe5fbfdc1f5a32903ac87182c75e6abe021ab003c8af6e6cc33e0d01e'
   end
 # rubocop: enable Metrics/LineLength