diff --git a/Gemfile b/Gemfile
index 292cf0c1a..74b25a873 100644
--- a/Gemfile
+++ b/Gemfile
@@ -12,7 +12,7 @@ gem 'marcel'
 gem 'mail', '~> 2.8.1'
 gem 'nokogiri', '~> 1.14.0'
 gem 'i18n', '~> 1.12.0'
-gem 'rbpdf', '~> 1.21.0'
+gem 'rbpdf', '~> 1.21.1'
 gem 'addressable'
 gem 'rubyzip', '~> 2.3.0'
 
diff --git a/lib/redmine/export/pdf.rb b/lib/redmine/export/pdf.rb
index 2ead7f7ca..e7133210d 100644
--- a/lib/redmine/export/pdf.rb
+++ b/lib/redmine/export/pdf.rb
@@ -149,7 +149,7 @@ module Redmine
         def self.attach(attachments, filename, encoding)
           filename_utf8 = Redmine::CodesetUtil.to_utf8(filename, encoding)
           atta = nil
-          if /^[^\/"]+\.(gif|jpg|jpe|jpeg|png)$/i.match?(filename_utf8)
+          if /^[^\/"]+\.(gif|jpg|jpe|jpeg|png|webp)$/i.match?(filename_utf8)
             atta = Attachment.latest_attach(attachments, filename_utf8)
           end
           if atta && atta.readable? && atta.visible?