diff --git a/CHANGELOG.md b/CHANGELOG.md
index e95d148f..7ffde049 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,7 +6,7 @@
 
 #### Fixes
 
-* Your contribution here.
+* [#683](https://github.com/ruby-grape/grape-swagger/pull/683): Fix handling of arrays of complex entities in params so that valid OpenAPI spec is generated - [@jdmurphy](https://github.com/jdmurphy).
 
 ###  0.29.0 (May 22, 2018)
 
diff --git a/lib/grape-swagger/doc_methods/move_params.rb b/lib/grape-swagger/doc_methods/move_params.rb
index 2a8c36c5..a73005b8 100644
--- a/lib/grape-swagger/doc_methods/move_params.rb
+++ b/lib/grape-swagger/doc_methods/move_params.rb
@@ -177,9 +177,16 @@ def object_type
         def prepare_nested_types(params)
           params.each do |param|
             next unless param[:items]
-            param[:type] = param[:items][:type] == 'array' ? 'string' : param[:items][:type]
+
+            param[:type] = if param[:items][:type] == 'array'
+                             'string'
+                           elsif param[:items].key?('$ref')
+                             param[:type] = 'object'
+                           else
+                             param[:items][:type]
+                           end
             param[:format] = param[:items][:format] if param[:items][:format]
-            param.delete(:items)
+            param.delete(:items) if param[:type] != 'object'
           end
         end
 
diff --git a/spec/lib/move_params_spec.rb b/spec/lib/move_params_spec.rb
index 92bf06cc..2d020b50 100644
--- a/spec/lib/move_params_spec.rb
+++ b/spec/lib/move_params_spec.rb
@@ -325,5 +325,193 @@
         it { expect(params).to eql expected_params }
       end
     end
+
+    describe 'prepare_nested_types' do
+      before :each do
+        subject.send(:prepare_nested_types, params)
+      end
+
+      let(:params) do
+        [
+          {
+            in: 'body',
+            name: 'address[street_lines]',
+            description: 'street lines',
+            type: 'array',
+            items: {
+              type: 'string'
+            },
+            required: true
+          }
+        ]
+      end
+
+      context 'when params contains nothing with :items key' do
+        let(:params) do
+          [
+            {
+              in: 'body',
+              name: 'phone_number',
+              description: 'phone number',
+              type: 'string',
+              required: true
+            }
+          ]
+        end
+
+        let(:expected_params) do
+          [
+            {
+              in: 'body',
+              name: 'phone_number',
+              description: 'phone number',
+              type: 'string',
+              required: true
+            }
+          ]
+        end
+
+        it 'does nothing' do
+          expect(params).to eq expected_params
+        end
+      end
+
+      context 'when params contains :items key with array type' do
+        let(:params) do
+          [
+            {
+              in: 'body',
+              name: 'address_street_lines',
+              description: 'street lines',
+              type: 'array',
+              items: {
+                type: 'array'
+              },
+              required: true
+            }
+          ]
+        end
+
+        let(:expected_params) do
+          [
+            {
+              in: 'body',
+              name: 'address_street_lines',
+              description: 'street lines',
+              type: 'string',
+              required: true
+            }
+          ]
+        end
+
+        it 'sets type to string and removes :items' do
+          expect(params).to eq expected_params
+        end
+      end
+
+      context 'when params contains :items key with $ref' do
+        let(:params) do
+          [
+            {
+              in: 'body',
+              name: 'address_street_lines',
+              description: 'street lines',
+              type: 'array',
+              items: {
+                '$ref' => '#/definitions/StreetLine'
+              },
+              required: true
+            }
+          ]
+        end
+
+        let(:expected_params) do
+          [
+            {
+              in: 'body',
+              name: 'address_street_lines',
+              description: 'street lines',
+              type: 'object',
+              items: {
+                '$ref' => '#/definitions/StreetLine'
+              },
+              required: true
+            }
+          ]
+        end
+
+        it 'sets type to object and does not remove :items' do
+          expect(params).to eq expected_params
+        end
+      end
+
+      context 'when params contains :items without $ref or array type' do
+        let(:params) do
+          [
+            {
+              in: 'body',
+              name: 'address_street_lines',
+              description: 'street lines',
+              type: 'array',
+              items: {
+                type: 'string'
+              },
+              required: true
+            }
+          ]
+        end
+
+        let(:expected_params) do
+          [
+            {
+              in: 'body',
+              name: 'address_street_lines',
+              description: 'street lines',
+              type: 'string',
+              required: true
+            }
+          ]
+        end
+
+        it 'sets type to :items :type and removes :items' do
+          expect(params).to eq expected_params
+        end
+      end
+
+      context 'when params contains :items key with :format' do
+        let(:params) do
+          [
+            {
+              in: 'body',
+              name: 'street_number',
+              description: 'street number',
+              type: 'array',
+              items: {
+                type: 'integer',
+                format: 'int32'
+              },
+              required: true
+            }
+          ]
+        end
+
+        let(:expected_params) do
+          [
+            {
+              in: 'body',
+              name: 'street_number',
+              description: 'street number',
+              type: 'integer',
+              format: 'int32',
+              required: true
+            }
+          ]
+        end
+
+        it 'sets format and removes :items' do
+          expect(params).to eq expected_params
+        end
+      end
+    end
   end
 end