diff --git a/lib/yard/parser/ruby/ast_node.rb b/lib/yard/parser/ruby/ast_node.rb
index 61c941c95..123ac87db 100644
--- a/lib/yard/parser/ruby/ast_node.rb
+++ b/lib/yard/parser/ruby/ast_node.rb
@@ -412,7 +412,14 @@ def unnamed_end_params
 
         def double_splat_param
           return nil unless YARD.ruby2?
-          self[-2] if self[-2].is_a?(AstNode) && self[-2].type == :ident
+          if (node = self[-2]).is_a?(AstNode)
+            if node.type == :ident
+              node
+            elsif node.type == :kwrest_param
+              # See https://bugs.ruby-lang.org/issues/12387
+              node.last
+            end
+          end
         end
 
         def block_param
diff --git a/lib/yard/rubygems/specification.rb b/lib/yard/rubygems/specification.rb
index 16bbb7eac..905ba067a 100644
--- a/lib/yard/rubygems/specification.rb
+++ b/lib/yard/rubygems/specification.rb
@@ -35,8 +35,16 @@ def _dump_with_rdoc(limit)
     alias _dump_without_rdoc _dump
     alias _dump _dump_with_rdoc
 
-    @@default_value[:has_rdoc] = true if defined?(@@default_value)
-    @@attributes << 'has_rdoc' if defined?(@@attributes)
-    @@nil_attributes << 'has_rdoc' if defined?(@@nil_attributes)
+    if class_variable_defined?(:@@default_value)
+      if @@default_value.frozen?
+        t = @@default_value.dup
+        t[:has_rdoc] = true
+        @@default_value = t.freeze
+      else
+        @@default_value[:has_rdoc] = true
+      end
+    end
+    @@attributes << 'has_rdoc' if class_variable_defined?(:@@attributes)
+    @@nil_attributes << 'has_rdoc' if class_variable_defined?(:@@nil_attributes)
   end
 end