diff --git a/README.md b/README.md
index d5eaf51..f49ab2e 100644
--- a/README.md
+++ b/README.md
@@ -149,6 +149,14 @@ param :order, String, in: ["ASC", "DESC"], raise: true
 one_of :q, :categories, raise: true
 ```
 
+## Nested Params
+
+Passing a `scope` option will provide validation for nested params, e.g. for GET parameter `q[order_id_eq]=4`:
+
+```ruby
+param :order_id_eq, Integer, scope: :q, min: 1, max: 2147483647
+```
+
 ## Contact
 
 Mattt Thompson ([@mattt](http://twitter.com/mattt))
diff --git a/lib/sinatra/param.rb b/lib/sinatra/param.rb
index 7762b84..73ae28e 100644
--- a/lib/sinatra/param.rb
+++ b/lib/sinatra/param.rb
@@ -13,28 +13,31 @@ class InvalidParameterError < StandardError
 
     def param(name, type, options = {})
       name = name.to_s
+      params = self.params # local variable with same neme as method.
 
-      return unless params.member?(name) or options[:default] or options[:required]
+      # Nested params
+      scope = options[:scope]
+      params = params[scope] if scope && params[scope].is_a?(Hash)
 
-      begin
-        params[name] = coerce(params[name], type, options)
-        params[name] = (options[:default].call if options[:default].respond_to?(:call)) || options[:default] if params[name].nil? and options[:default]
-        params[name] = options[:transform].to_proc.call(params[name]) if params[name] and options[:transform]
-        validate!(params[name], options)
-      rescue InvalidParameterError => exception
-        if options[:raise] or (settings.raise_sinatra_param_exceptions rescue false)
-          exception.param, exception.options = name, options
-          raise exception
-        end
+      return unless params.member?(name) or options[:default] or options[:required]
 
-        error = exception.to_s
+      params[name] = coerce(params[name], type, options)
+      params[name] = (options[:default].call if options[:default].respond_to?(:call)) || options[:default] if params[name].nil? and options[:default]
+      params[name] = options[:transform].to_proc.call(params[name]) if params[name] and options[:transform]
+      validate!(params[name], options)
+    rescue InvalidParameterError => exception
+      if options[:raise] or (settings.raise_sinatra_param_exceptions rescue false)
+        exception.param, exception.options = name, options
+        raise exception
+      end
 
-        if content_type and content_type.match(mime_type(:json))
-          error = {message: error, errors: {name => exception.message}}.to_json
-        end
+      error = exception.to_s
 
-        halt 400, error
+      if content_type and content_type.match(mime_type(:json))
+        error = {message: error, errors: {name => exception.message}}.to_json
       end
+
+      halt 400, error
     end
 
     def one_of(*args)
diff --git a/spec/dummy/app.rb b/spec/dummy/app.rb
index f577123..27d61ec 100644
--- a/spec/dummy/app.rb
+++ b/spec/dummy/app.rb
@@ -175,6 +175,11 @@ class App < Sinatra::Base
     params.to_json
   end
 
+  get '/validation/scoped/max' do
+    param :arg, Integer, scope: :q, max: 20
+    params.to_json
+  end
+
   get '/validation/min_length' do
     param :arg, String, min_length: 5
     params.to_json
diff --git a/spec/parameter_raise_spec.rb b/spec/parameter_raise_spec.rb
index 997b063..d4a1cfe 100644
--- a/spec/parameter_raise_spec.rb
+++ b/spec/parameter_raise_spec.rb
@@ -5,7 +5,7 @@
     it 'should raise error when option is specified' do
       expect {
         get('/raise/validation/required')
-      }.to raise_error
+      }.to raise_error Sinatra::Param::InvalidParameterError
     end
   end
 
@@ -13,13 +13,13 @@
     params = {a: 1, b: 2, c: 3}
     expect {
       get('/raise/one_of/3', params)
-    }.to raise_error
+    }.to raise_error Sinatra::Param::InvalidParameterError
   end
 
   it 'should raise error when no parameters are specified' do
     params = {}
     expect {
       get('/raise/any_of', params)
-    }.to raise_error
+    }.to raise_error Sinatra::Param::InvalidParameterError
   end
 end
diff --git a/spec/parameter_validations_spec.rb b/spec/parameter_validations_spec.rb
index 46114e4..d2cbf73 100644
--- a/spec/parameter_validations_spec.rb
+++ b/spec/parameter_validations_spec.rb
@@ -160,6 +160,21 @@
         expect(response.status).to eq(200)
       end
     end
+
+    context 'nested params' do
+      it 'returns 400 on requests with a value larger than max' do
+        get('/validation/scoped/max', q: { arg: 100 }) do |response|
+          expect(response.status).to eq(400)
+          expect(JSON.parse(response.body)['message']).to eq("Parameter cannot be greater than 20")
+        end
+      end
+
+      it 'returns 200 on requests with a value smaller than max' do
+        get('/validation/scoped/max', q: { arg: 2 }) do |response|
+          expect(response.status).to eq(200)
+        end
+      end
+    end
   end
 
   describe 'min_length' do