diff --git a/lib/openapi_first/builder.rb b/lib/openapi_first/builder.rb
index cddd529f..e6cc1c5f 100644
--- a/lib/openapi_first/builder.rb
+++ b/lib/openapi_first/builder.rb
@@ -110,7 +110,11 @@ def parse_parameters(parameters)
     def resolve_parameters(parameters)
       parameters&.map do |parameter|
         result = parameter.resolved
-        result['schema'] = parameter['schema'].resolved
+        result['schema'] = if parameter['content'] && parameter['content']['application/json']
+                             parameter['content']['application/json']['schema'].resolved
+                           else
+                             parameter['schema'].resolved
+                           end
         result
       end.to_a
     end
diff --git a/spec/data/query-parameter-validation.yaml b/spec/data/query-parameter-validation.yaml
index 50ad31cd..94b764c6 100644
--- a/spec/data/query-parameter-validation.yaml
+++ b/spec/data/query-parameter-validation.yaml
@@ -22,6 +22,19 @@ paths:
           schema:
             type: string
         - $ref: './components/parameters/filter.yaml'
+        - name: json_filter
+          in: query
+          description: Filter results
+          example: '{"tag": "foo"}'
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  tag:
+                    type: string
+                  other:
+                    type: object
         - name: limit
           in: query
           description: How many items to return at one time (max 100)
diff --git a/spec/middlewares/request_validation/query_parameter_validation_spec.rb b/spec/middlewares/request_validation/query_parameter_validation_spec.rb
index 8b850f9d..951f4cc0 100644
--- a/spec/middlewares/request_validation/query_parameter_validation_spec.rb
+++ b/spec/middlewares/request_validation/query_parameter_validation_spec.rb
@@ -349,6 +349,14 @@ def last_params
         expect(last_response.status).to eq(200), last_response.body
         expect(last_params.dig('filter', 'id')).to eq 100
       end
+
+      it 'converts JSON encoded params' do
+        get '/search', params.merge(json_filter: { tag: 'dogs' }.to_json)
+        expect(last_response.status).to eq(200), last_response.body
+
+        get '/search', params.merge(json_filter: { tag: true }.to_json)
+        expect(last_response.status).to eq(400), last_response.body
+      end
     end
   end
 end