diff --git a/.gitignore b/.gitignore
index cdea425..50f9cac 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,6 +3,7 @@
 .bundle
 .config
 .yardoc
+.vendor
 Gemfile.lock
 InstalledFiles
 _yardoc
@@ -16,4 +17,5 @@ test/tmp
 test/version_tmp
 tmp
 tags
+vendor
 .DS_Store
diff --git a/Gemfile.lock b/Gemfile.lock
index 65eca8d..55ad0f6 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,78 +1,89 @@
 PATH
   remote: .
   specs:
-    stackprof-webnav (1.0.3)
+    stackprof-webnav (1.0.4)
       better_errors (~> 1.1.0)
-      haml (~> 5.1.2)
+      haml (~> 6.0)
       rackup (>= 1.0.0, < 3.0.0)
       ruby-graphviz (~> 1.2.4)
-      sinatra (>= 2.1.0, < 5.0.0)
-      sinatra-contrib (>= 2.1.0, < 5.0.0)
+      sinatra (~> 4.1.0)
+      sinatra-contrib (~> 4.1.0)
       stackprof (>= 0.2.13)
       webrick (~> 1.7)
 
 GEM
   remote: https://rubygems.org/
   specs:
+    base64 (0.3.0)
     better_errors (1.1.0)
       coderay (>= 1.0.0)
       erubis (>= 2.6.6)
-    coderay (1.1.2)
-    diff-lcs (1.3)
+    coderay (1.1.3)
+    diff-lcs (1.6.2)
     erubis (2.7.0)
-    haml (5.1.2)
-      temple (>= 0.8.0)
+    haml (6.3.0)
+      temple (>= 0.8.2)
+      thor
       tilt
-    method_source (0.9.2)
+    logger (1.7.0)
+    method_source (1.1.0)
     multi_json (1.15.0)
-    mustermann (1.1.1)
+    mustermann (3.0.3)
       ruby2_keywords (~> 0.0.1)
-    pry (0.12.2)
-      coderay (~> 1.1.0)
-      method_source (~> 0.9.0)
-    rack (2.2.3)
-    rack-protection (2.1.0)
-      rack
-    rack-test (1.1.0)
-      rack (>= 1.0, < 3)
-    rackup (1.0.0)
-      rack (< 3)
-      webrick
+    pry (0.15.2)
+      coderay (~> 1.1)
+      method_source (~> 1.0)
+    rack (3.1.16)
+    rack-protection (4.1.1)
+      base64 (>= 0.1.0)
+      logger (>= 1.6.0)
+      rack (>= 3.0.0, < 4)
+    rack-session (2.1.1)
+      base64 (>= 0.1.0)
+      rack (>= 3.0.0)
+    rack-test (2.2.0)
+      rack (>= 1.3)
+    rackup (2.2.1)
+      rack (>= 3)
     rake (10.5.0)
-    rexml (3.2.5)
+    rexml (3.4.1)
     rspec (3.9.0)
       rspec-core (~> 3.9.0)
       rspec-expectations (~> 3.9.0)
       rspec-mocks (~> 3.9.0)
-    rspec-core (3.9.0)
-      rspec-support (~> 3.9.0)
-    rspec-expectations (3.9.0)
+    rspec-core (3.9.3)
+      rspec-support (~> 3.9.3)
+    rspec-expectations (3.9.4)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.9.0)
-    rspec-mocks (3.9.0)
+    rspec-mocks (3.9.1)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.9.0)
-    rspec-support (3.9.0)
+    rspec-support (3.9.4)
     ruby-graphviz (1.2.5)
       rexml
     ruby2_keywords (0.0.5)
-    sinatra (2.1.0)
-      mustermann (~> 1.0)
-      rack (~> 2.2)
-      rack-protection (= 2.1.0)
+    sinatra (4.1.1)
+      logger (>= 1.6.0)
+      mustermann (~> 3.0)
+      rack (>= 3.0.0, < 4)
+      rack-protection (= 4.1.1)
+      rack-session (>= 2.0.0, < 3)
       tilt (~> 2.0)
-    sinatra-contrib (2.1.0)
-      multi_json
-      mustermann (~> 1.0)
-      rack-protection (= 2.1.0)
-      sinatra (= 2.1.0)
+    sinatra-contrib (4.1.1)
+      multi_json (>= 0.0.2)
+      mustermann (~> 3.0)
+      rack-protection (= 4.1.1)
+      sinatra (= 4.1.1)
       tilt (~> 2.0)
-    stackprof (0.2.17)
-    temple (0.8.2)
-    tilt (2.0.10)
-    webrick (1.7.0)
+    stackprof (0.2.27)
+    temple (0.10.3)
+    thor (1.3.2)
+    tilt (2.6.0)
+    webrick (1.9.1)
 
 PLATFORMS
+  arm64-darwin-23
   ruby
 
 DEPENDENCIES
@@ -84,4 +95,4 @@ DEPENDENCIES
   stackprof-webnav!
 
 BUNDLED WITH
-   2.2.18
+   2.6.5
diff --git a/lib/stackprof-webnav/server.rb b/lib/stackprof-webnav/server.rb
index cffd163..27d8b7e 100644
--- a/lib/stackprof-webnav/server.rb
+++ b/lib/stackprof-webnav/server.rb
@@ -5,6 +5,9 @@
 require_relative 'dump'
 require 'sinatra/reloader' if development?
 require 'ruby-graphviz'
+require 'ostruct'
+
+Haml::Template.options[:escape_html] = false
 
 module StackProf
   module Webnav
diff --git a/stackprof-webnav.gemspec b/stackprof-webnav.gemspec
index a3e64d7..8a238d4 100644
--- a/stackprof-webnav.gemspec
+++ b/stackprof-webnav.gemspec
@@ -21,13 +21,13 @@ Gem::Specification.new do |spec|
   spec.bindir = 'bin'
   spec.executables << 'stackprof-webnav'
 
-  spec.add_dependency "sinatra", ">= 2.1.0", "< 5.0.0"
-  spec.add_dependency "haml", "~> 5.1.2"
+  spec.add_dependency "sinatra", "~> 4.1.0"
+  spec.add_dependency "haml", "~> 6.0"
   spec.add_dependency "stackprof", ">= 0.2.13"
   spec.add_dependency "better_errors", "~> 1.1.0"
   spec.add_dependency "rackup", ">= 1.0.0", "< 3.0.0"
   spec.add_dependency "ruby-graphviz", "~> 1.2.4"
-  spec.add_dependency "sinatra-contrib", ">= 2.1.0", "< 5.0.0"
+  spec.add_dependency "sinatra-contrib", "~> 4.1.0"
   spec.add_dependency "webrick", "~> 1.7"
   spec.add_development_dependency "bundler", "~> 2.2"
   spec.add_development_dependency "rake", "~> 10.1"