diff --git a/lib/spec/openapi/utils.js b/lib/spec/openapi/utils.js
index b20200eb..af5ed9ed 100644
--- a/lib/spec/openapi/utils.js
+++ b/lib/spec/openapi/utils.js
@@ -182,7 +182,7 @@ function plainJsonObjectToOpenapi3 (container, jsonSchema, externalSchemas, secu
         }
 
         // description should be optional
-        if (jsonSchemaElement.description) result.description = jsonSchemaElement.description
+        if (jsonSchemaElement?.description) result.description = jsonSchemaElement.description
         return result
       }
       break
@@ -239,16 +239,16 @@ function resolveSchemaExamplesRecursive (schema) {
 function schemaToMedia (schema) {
   const media = { schema }
 
-  if (schema.examples?.length === 1) {
+  if (schema?.examples?.length === 1) {
     media.example = schema.examples[0]
     delete schema.examples
-  } else if (schema.examples?.length > 1) {
+  } else if (schema?.examples?.length > 1) {
     media.examples = convertExamplesArrayToObject(schema.examples)
     // examples is invalid property of media object schema
     delete schema.examples
   }
 
-  if (schema[xExamples]) {
+  if (schema && schema[xExamples]) {
     media.examples = schema[xExamples]
     delete schema[xExamples]
   }
@@ -451,7 +451,7 @@ function prepareOpenapiMethod (schema, ref, openapiObject, url) {
   ]
     .reduce((acc, securitySchemeGroup) => {
       Object.keys(securitySchemeGroup).forEach((securitySchemeLabel) => {
-        const scheme = openapiObject.components.securitySchemes[securitySchemeLabel]
+        const scheme = openapiObject.components.securitySchemes[securitySchemeLabel] ?? {}
         const isBearer = scheme.type === 'http' && scheme.scheme === 'bearer'
         const category = isBearer ? 'header' : scheme.in
         const name = isBearer ? 'authorization' : scheme.name