diff --git a/Gemfile.lock b/Gemfile.lock
index 14199ba2..3c6fb894 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -4,7 +4,7 @@ PATH
     mailcatcher (0.6.0)
       activesupport (>= 3.0.0, < 4.1)
       eventmachine (~> 1.0.0)
-      haml (>= 3.1, < 4.1)
+      haml (>= 3.1, < 5.2)
       mail (~> 2.3)
       sinatra (~> 1.2)
       skinny (~> 0.2.3)
@@ -14,7 +14,7 @@ PATH
 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (3.2.17)
+    activesupport (3.2.22.5)
       i18n (~> 0.6, >= 0.6.4)
       multi_json (~> 1.0)
     childprocess (0.5.1)
@@ -28,25 +28,26 @@ GEM
       chunky_png (~> 1.2)
       fssm (>= 0.2.7)
       sass (~> 3.2.17)
-    daemons (1.1.9)
-    eventmachine (1.0.3)
+    concurrent-ruby (1.1.7)
+    daemons (1.3.1)
+    eventmachine (1.0.9.1)
     execjs (2.0.2)
     ffi (1.9.3)
     fssm (0.2.10)
-    haml (4.0.5)
+    haml (5.1.2)
+      temple (>= 0.8.0)
       tilt
     hike (1.2.3)
-    i18n (0.6.9)
+    i18n (0.9.5)
+      concurrent-ruby (~> 1.0)
     json (1.8.1)
-    mail (2.5.4)
-      mime-types (~> 1.16)
-      treetop (~> 1.4.8)
-    mime-types (1.25.1)
+    mail (2.7.1)
+      mini_mime (>= 0.1.1)
+    mini_mime (1.0.2)
     minitest (5.3.1)
     multi_json (1.9.2)
-    polyglot (0.3.4)
     rack (1.5.2)
-    rack-protection (1.5.2)
+    rack-protection (1.5.5)
       rack
     rake (10.1.1)
     rdoc (4.1.1)
@@ -58,13 +59,13 @@ GEM
       multi_json (~> 1.0)
       rubyzip (~> 1.0)
       websocket (~> 1.0.4)
-    sinatra (1.4.4)
-      rack (~> 1.4)
+    sinatra (1.4.8)
+      rack (~> 1.5)
       rack-protection (~> 1.4)
-      tilt (~> 1.3, >= 1.3.4)
-    skinny (0.2.3)
+      tilt (>= 1.3, < 3)
+    skinny (0.2.4)
       eventmachine (~> 1.0.0)
-      thin (~> 1.5.0)
+      thin (>= 1.5, < 1.7)
     sprockets (2.12.0)
       hike (~> 1.2)
       multi_json (~> 1.0)
@@ -75,15 +76,13 @@ GEM
     sprockets-sass (1.0.3)
       sprockets (~> 2.0)
       tilt (~> 1.1)
-    sqlite3 (1.3.9)
+    sqlite3 (1.4.2)
+    temple (0.8.2)
     thin (1.5.1)
       daemons (>= 1.0.9)
       eventmachine (>= 0.12.6)
       rack (>= 1.0.0)
     tilt (1.4.1)
-    treetop (1.4.15)
-      polyglot
-      polyglot (>= 0.3.1)
     uglifier (2.5.0)
       execjs (>= 0.3.0)
       json (>= 1.8.0)
diff --git a/mailcatcher.gemspec b/mailcatcher.gemspec
index a943e058..ed6ca97b 100644
--- a/mailcatcher.gemspec
+++ b/mailcatcher.gemspec
@@ -32,7 +32,7 @@ Gem::Specification.new do |s|
 
   s.add_dependency "activesupport", ">= 3.0.0", "< 4.1"
   s.add_dependency "eventmachine", "~> 1.0.0"
-  s.add_dependency "haml", ">= 3.1", "< 4.1"
+  s.add_dependency "haml", ">= 3.1", "< 5.2"
   s.add_dependency "mail", "~> 2.3"
   s.add_dependency "sinatra", "~> 1.2"
   s.add_dependency "sqlite3", "~> 1.3"