diff --git a/Gemfile.lock b/Gemfile.lock
index 605f5b1..c20b6c2 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -27,7 +27,7 @@ GEM
     deep_merge (1.2.1)
     diff-lcs (1.3)
     docile (1.1.5)
-    ffi (1.9.25)
+    ffi (1.16.3)
     formatador (0.2.5)
     guard (2.15.0)
       formatador (>= 0.2.4)
@@ -48,13 +48,12 @@ GEM
     i18n (1.8.10)
       concurrent-ruby (~> 1.0)
     json (2.3.1)
-    listen (3.1.5)
-      rb-fsevent (~> 0.9, >= 0.9.4)
-      rb-inotify (~> 0.9, >= 0.9.7)
-      ruby_dep (~> 1.2)
+    listen (3.8.0)
+      rb-fsevent (~> 0.10, >= 0.10.3)
+      rb-inotify (~> 0.9, >= 0.9.10)
     lumberjack (1.0.13)
     method_source (0.9.2)
-    mini_portile2 (2.5.1)
+    mini_portile2 (2.8.5)
     minitest (5.14.4)
     mustermann (1.1.1)
       ruby2_keywords (~> 0.0.1)
@@ -62,8 +61,8 @@ GEM
       hansi (~> 0.2.0)
       mustermann (= 1.1.1)
     nenv (0.3.0)
-    nokogiri (1.11.4)
-      mini_portile2 (~> 2.5.0)
+    nokogiri (1.16.2)
+      mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
     notiffany (0.1.1)
       nenv (~> 0.1)
@@ -72,11 +71,11 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
     public_suffix (4.0.6)
-    racc (1.5.2)
+    racc (1.7.3)
     rake (13.0.1)
-    rb-fsevent (0.10.3)
-    rb-inotify (0.9.10)
-      ffi (>= 0.5.0, < 2)
+    rb-fsevent (0.11.2)
+    rb-inotify (0.10.1)
+      ffi (~> 1.0)
     rspec (3.8.0)
       rspec-core (~> 3.8.0)
       rspec-expectations (~> 3.8.0)
@@ -93,7 +92,6 @@ GEM
       rspec-support (~> 3.8.0)
     rspec-support (3.8.0)
     ruby2_keywords (0.0.4)
-    ruby_dep (1.5.0)
     shellany (0.0.1)
     simplecov (0.15.1)
       docile (~> 1.1.0)
diff --git a/lib/oas_parser.rb b/lib/oas_parser.rb
index 66fc615..3826e7e 100644
--- a/lib/oas_parser.rb
+++ b/lib/oas_parser.rb
@@ -2,11 +2,12 @@
 require 'uri'
 require 'yaml'
 require 'active_support/core_ext/object/blank'
+require 'active_support/core_ext/array/conversions'
 require 'active_support/core_ext/hash/conversions'
 require 'nokogiri'
 
 require 'addressable/uri'
-require 'deep_merge'
+require 'deep_merge/rails_compat'
 
 require_relative 'oas_parser/path.rb'
 require_relative 'oas_parser/payload.rb'
diff --git a/lib/oas_parser/parser.rb b/lib/oas_parser/parser.rb
index 1f7576d..9b700fa 100644
--- a/lib/oas_parser/parser.rb
+++ b/lib/oas_parser/parser.rb
@@ -1,7 +1,7 @@
 module OasParser
   class Parser
     def self.resolve(path)
-      content = YAML.load_file(path)
+      content = YAML.load_file(path, permitted_classes: [Time])
       Parser.new(path, content).resolve
     end
 
diff --git a/lib/oas_parser/property.rb b/lib/oas_parser/property.rb
index eb7a646..aa11a1b 100644
--- a/lib/oas_parser/property.rb
+++ b/lib/oas_parser/property.rb
@@ -27,7 +27,7 @@ def convert_property_schema_to_properties(schema)
       if schema['allOf']
         schema['properties'] = {}
         schema['allOf'].each do |p|
-          schema['properties'].deep_merge!(p['properties'])
+          schema['properties'].deeper_merge!(p['properties'])
         end
         schema.delete('allOf')
       end
diff --git a/lib/oas_parser/request_body.rb b/lib/oas_parser/request_body.rb
index 852e48f..f923569 100644
--- a/lib/oas_parser/request_body.rb
+++ b/lib/oas_parser/request_body.rb
@@ -49,7 +49,7 @@ def deep_safe_merge(source_hash, new_hash)
          if new.respond_to?(:blank) && new.blank?
            old
          elsif (old.kind_of?(Hash) and new.kind_of?(Hash))
-           old.deep_merge(new)
+           old.deeper_merge(new)
          elsif (old.kind_of?(Array) and new.kind_of?(Array))
            old.concat(new).uniq
          else
diff --git a/lib/oas_parser/response_parser.rb b/lib/oas_parser/response_parser.rb
index 2499f90..633f6bc 100644
--- a/lib/oas_parser/response_parser.rb
+++ b/lib/oas_parser/response_parser.rb
@@ -92,7 +92,7 @@ def parse_object(object)
 
       if object['allOf']
         merged_object = { 'type' => 'object' }
-        object['allOf'].each { |o| merged_object.deep_merge!(o) }
+        object['allOf'].each { |o| merged_object.deeper_merge!(o) }
         return parameter_value(merged_object)
       elsif object['properties']
         o = {}