diff --git a/Gemfile b/Gemfile
index 106cbf2eff6d..4c7f40441afc 100644
--- a/Gemfile
+++ b/Gemfile
@@ -385,7 +385,7 @@ group :development, :test do
 end
 
 # API gems
-gem "grape", "~> 3.2.0"
+gem "grape", "~> 3.3.0"
 gem "grape_logging", "~> 3.0.0"
 gem "roar", "~> 1.2.0"
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 071a6a3b7f45..1592533ae033 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -693,13 +693,13 @@ GEM
       os (>= 0.9, < 2.0)
       pstore (~> 0.1)
       signet (>= 0.16, < 2.a)
-    grape (3.2.1)
+    grape (3.3.0)
       activesupport (>= 7.2)
-      dry-configurable
+      dry-configurable (>= 1.0)
       dry-types (>= 1.1)
-      mustermann-grape (~> 1.1.0)
-      rack (>= 2)
-      zeitwerk
+      mustermann (>= 4.0)
+      rack (>= 2.2.4)
+      zeitwerk (>= 2.6)
     grape_logging (3.0.0)
       grape (>= 2.4.0)
       rack
@@ -856,8 +856,6 @@ GEM
     msgpack (1.8.3)
     multi_json (1.21.1)
     mustermann (4.0.0)
-    mustermann-grape (1.1.0)
-      mustermann (>= 1.0.0)
     net-http (0.9.1)
       uri (>= 0.11.1)
     net-imap (0.6.4.1)
@@ -1638,7 +1636,7 @@ DEPENDENCIES
   good_job (~> 4.19.1)
   google-apis-gmail_v1
   googleauth
-  grape (~> 3.2.0)
+  grape (~> 3.3.0)
   grape_logging (~> 3.0.0)
   grids!
   html-pipeline (~> 2.14.0)
@@ -1967,7 +1965,7 @@ CHECKSUMS
   google-protobuf (4.35.1-x86_64-linux-musl) sha256=91890eb0002934a339fdb7d77a147c46b7474b6799db27872b747b905837f744
   googleapis-common-protos-types (1.23.0) sha256=992e740a523794d9fc5f29a504465d8fc737aaa16c930fe7228e3346860faf0a
   googleauth (1.17.1) sha256=0f7e6fc70e204cee1b2d71f1e1de2d3b349d432404197fe68ebf7fa23d0821b9
-  grape (3.2.1) sha256=448072f55904e5a4dca2e3781f0a373942514be65402cafb6177f5bc73db1b94
+  grape (3.3.0) sha256=65e48ad2e396d25304cde91f0ec307e6cafc76bb78adcdb070fbbcc2ec3d4361
   grape_logging (3.0.0) sha256=7b62d984ce96df15d120508668debe307e6a59ac1c511f1d9b5f3b4bea793e13
   gravatar_image_tag (1.2.0) sha256=eb5630fea846b711e713b934a0178fb9785f02f4eb9ced8d6faa4d537c40fdcf
   grids (1.0.0)
@@ -2032,7 +2030,6 @@ CHECKSUMS
   msgpack (1.8.3) sha256=8bda4a6428d3244e50d6bd55854d354edbada88a4e1f4f5731a39a0f86bee6a1
   multi_json (1.21.1) sha256=e6126a31808e3b4d19f483c775ceac34df190dffa62adfb63a165ee14ba68080
   mustermann (4.0.0) sha256=91f67411bb208d1d93c41e6128cb3b0f8ddd9ec7c45966f1007e1c43c08040d7
-  mustermann-grape (1.1.0) sha256=8d258a986004c8f01ce4c023c0b037c168a9ed889cf5778068ad54398fa458c5
   my_page (1.0.0)
   net-http (0.9.1) sha256=25ba0b67c63e89df626ed8fac771d0ad24ad151a858af2cc8e6a716ca4336996
   net-imap (0.6.4.1) sha256=29f0360d75a7efd3539f16ac1957dea5c0a51ddeceb348db4553c3120914ea0d
diff --git a/lib/api/utilities/grape_helper.rb b/lib/api/utilities/grape_helper.rb
index b1ffd7915c5a..32f6c52773b0 100644
--- a/lib/api/utilities/grape_helper.rb
+++ b/lib/api/utilities/grape_helper.rb
@@ -34,9 +34,9 @@ module GrapeHelper
       # outside of the Grape context. We use it outside of the Grape context because
       # OpenProject authentication happens in a middleware upstream of Grape.
       class GrapeError < Grape::Middleware::Error
-        def initialize(env)
+        def initialize(env, content_types:, format:)
+          super(nil, content_types:, format:)
           @env = env
-          @options = {}
         end
 
         def error!(message, status = nil, headers = nil, backtrace = nil, original_exception = nil)
@@ -45,13 +45,10 @@ def error!(message, status = nil, headers = nil, backtrace = nil, original_excep
       end
 
       def grape_error_for(env, api)
-        GrapeError.new(env).tap do |e|
-          e.options[:content_types] = api.content_types
-          e.options[:format] = "hal+json"
-        end
+        GrapeError.new(env, content_types: api.content_types, format: "hal+json")
       end
 
-      def error_response(rescued_error, error = nil, rescue_subclasses: nil, headers: -> { {} }, log: true)
+      def error_response(rescued_error, error = nil, rescue_subclasses: true, headers: -> { {} }, log: true)
         error_response_lambda = default_error_response(headers, log)
 
         response =
diff --git a/lib/api/utilities/json_gem_parser.rb b/lib/api/utilities/json_gem_parser.rb
deleted file mode 100644
index a097eafd55cd..000000000000
--- a/lib/api/utilities/json_gem_parser.rb
+++ /dev/null
@@ -1,11 +0,0 @@
-# Forces using the classic json gem when parsing.
-# This might be beneficial in cases where other parsers, orchestrated by MultiJSON misbehave.
-# This is e.g. the case with oj which sometimes turns numbers into BigDecimal values.
-module API::Utilities::JsonGemParser
-  def self.call(object, _)
-    ::Grape::Json.load(object, adapter: :json_gem)
-  rescue ::Grape::Json::ParseError
-    # handle JSON parsing errors via the rescue handlers or provide error message
-    raise Grape::Exceptions::InvalidMessageBody, "application/json"
-  end
-end
diff --git a/lib/api/v3/utilities/eprops_conversion.rb b/lib/api/v3/utilities/eprops_conversion.rb
index b1fbd702175b..c1ce154f4875 100644
--- a/lib/api/v3/utilities/eprops_conversion.rb
+++ b/lib/api/v3/utilities/eprops_conversion.rb
@@ -37,8 +37,9 @@ module EpropsConversion
         DECOMPRESS_CHUNK_SIZE = 16 * 1024
 
         def raise_invalid_eprops(error, i18n_key)
-          mapped_error = OpenStruct.new(params: [:eprops], message: I18n.t(i18n_key, message: error.message))
-          raise ::Grape::Exceptions::ValidationErrors.new errors: [mapped_error]
+          mapped_error = ::Grape::Exceptions::Validation.new(params: [:eprops],
+                                                             message: I18n.t(i18n_key, message: error.message))
+          raise ::Grape::Exceptions::ValidationErrors.new(exceptions: [mapped_error])
         end
 
         def transform_eprops
diff --git a/lib/open_project/patches/grape_dsl_routing.rb b/lib/open_project/patches/grape_dsl_routing.rb
index d95311b0b886..c7825b5a8d17 100644
--- a/lib/open_project/patches/grape_dsl_routing.rb
+++ b/lib/open_project/patches/grape_dsl_routing.rb
@@ -56,6 +56,6 @@ def patches
   end
 end
 
-OpenProject::Patches.patch_gem_version "grape", "3.2.1" do
+OpenProject::Patches.patch_gem_version "grape", "3.3.1" do
   Grape::DSL::Routing.include OpenProject::Patches::GrapeDslRouting
 end
diff --git a/modules/bim/app/controllers/bim/bcf/api/v2_1/viewpoints/api.rb b/modules/bim/app/controllers/bim/bcf/api/v2_1/viewpoints/api.rb
index 8a4b390d341f..6715a34e2a0f 100644
--- a/modules/bim/app/controllers/bim/bcf/api/v2_1/viewpoints/api.rb
+++ b/modules/bim/app/controllers/bim/bcf/api/v2_1/viewpoints/api.rb
@@ -29,9 +29,6 @@
 module Bim::Bcf::API::V2_1
   module Viewpoints
     class API < ::API::OpenProjectAPI
-      # Avoid oj parsing numbers into BigDecimal
-      parser :json, ::API::Utilities::JsonGemParser
-
       resources :viewpoints do
         get do
           @issue
diff --git a/modules/bim/app/formatters/bim/bcf/api/error_formatter/bcf_json.rb b/modules/bim/app/formatters/bim/bcf/api/error_formatter/bcf_json.rb
index 4c852c0fbf4e..9005647145a6 100644
--- a/modules/bim/app/formatters/bim/bcf/api/error_formatter/bcf_json.rb
+++ b/modules/bim/app/formatters/bim/bcf/api/error_formatter/bcf_json.rb
@@ -31,8 +31,8 @@ module API
     module ErrorFormatter
       class BcfJson < Grape::ErrorFormatter::Base
         class << self
-          def call(message, _backtrace, _options = {}, env = nil, _original_exception = nil)
-            present(message, env)
+          def call(error:, env: nil, **_)
+            present(error.message, env)
           end
         end
       end