diff --git a/lib/rspec_api_documentation/views/api_blueprint_index.rb b/lib/rspec_api_documentation/views/api_blueprint_index.rb
index ef42c1fa..a5b157d3 100644
--- a/lib/rspec_api_documentation/views/api_blueprint_index.rb
+++ b/lib/rspec_api_documentation/views/api_blueprint_index.rb
@@ -67,6 +67,11 @@ def format_route(example)
       #     properties_description: "required, string"
       #   }
       def fields(property_name, examples)
+        possible_parameters_values = examples.map do |example|
+          parameters = example.metadata[:extended_parameters] || []
+          next parameters.map { |parameter| [parameter[:name], parameter[:value]] }.to_h
+        end
+
         examples
           .map { |example| example.metadata[property_name] }
           .flatten
@@ -79,7 +84,19 @@ def fields(property_name, examples)
             else
               properties << 'optional'
             end
-            properties << property[:type] if property[:type]
+
+            if property.key?(:type)
+              properties << property[:type] if property[:type]
+            else
+              possible_values = possible_parameters_values.map { |parameters| parameters[property[:name]] }
+              possible_types = possible_values.map { |value| guess_type(value) }
+
+              possible_types.uniq!
+              possible_types.compact!
+
+              properties.concat(possible_types)
+            end
+
             if properties.count > 0
               property[:properties_description] = properties.join(", ")
             else
@@ -96,6 +113,21 @@ def fields(property_name, examples)
           end
       end
 
+      def guess_type(value)
+        case value
+        when TrueClass then :boolean
+        when FalseClass then :boolean
+        when Array then :array
+        when Integer then :integer
+        when Float then :number
+        when String then :string
+        when Rack::Test::UploadedFile then :file
+        when NilClass then nil
+        else
+          puts "Warning: unknown type of value #{value}"
+        end
+      end
+
       # When no `description` was specified for a parameter, the DSL class
       # is making `description = "#{scope} #{name}"`, which is bad because it
       # assumes that all formats want this behavior. To avoid changing there
diff --git a/spec/views/api_blueprint_index_spec.rb b/spec/views/api_blueprint_index_spec.rb
index 1d526597..a1ce7c1e 100644
--- a/spec/views/api_blueprint_index_spec.rb
+++ b/spec/views/api_blueprint_index_spec.rb
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 require 'spec_helper'
+require 'rack/test'
 require 'rspec_api_documentation/dsl'
 
 describe RspecApiDocumentation::Views::ApiBlueprintIndex do
@@ -164,4 +165,52 @@
       end
     end
   end
+
+  describe '#guess_type' do
+    let(:index) { RspecApiDocumentation::Index.new }
+    let(:order_route) { subject.sections[0][:routes][0] }
+
+    resource "Order" do
+      route '/orders', 'Order' do
+        post "orders" do
+          parameter :desc, required: true
+          parameter :price, required: true
+
+          let(:desc) { "A test order" }
+          let(:price) { 13 }
+
+          let(:config) { RspecApiDocumentation::Configuration.new }
+
+          before do
+            expect(client).to receive(:post)
+            do_request
+
+            index.examples << RspecApiDocumentation::Example.new(client.example, config)
+          end
+
+          it "should guess the parameter type" do
+            order_examples = order_route[:http_methods].map { |http_method| http_method[:examples] }.flatten
+            expect(order_examples.size).to eq 1
+            expect(order_route[:route]).to eq "/orders"
+            expect(order_route[:route_name]).to eq "Order"
+            expect(order_route[:has_parameters?]).to eq true
+            expect(order_route[:parameters]).to eq [
+              {
+                required: true,
+                name: "desc",
+                description: nil,
+                properties_description: "required, string"
+              },
+              {
+                required: true,
+                name: "price",
+                description: nil,
+                properties_description: "required, integer"
+              }
+            ]
+          end
+        end
+      end
+    end
+  end
 end