diff --git a/modules/openapi-generator/src/main/resources/swift5/modelObject.mustache b/modules/openapi-generator/src/main/resources/swift5/modelObject.mustache
index 336ee3467c85..da0d44247fc0 100644
--- a/modules/openapi-generator/src/main/resources/swift5/modelObject.mustache
+++ b/modules/openapi-generator/src/main/resources/swift5/modelObject.mustache
@@ -76,16 +76,17 @@
     // Decodable protocol methods
 
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}}{{#objcCompatible}} required{{/objcCompatible}} init(from decoder: Decoder) throws {
-        let container = try decoder.container(keyedBy: String.self)
+        let container = try decoder.container(keyedBy: CodingKeys.self)
 
         {{#allVars}}
-        {{{name}}} = try container.decode{{#required}}{{#isNullable}}IfPresent{{/isNullable}}{{/required}}{{^required}}IfPresent{{/required}}({{{datatypeWithEnum}}}.self, forKey: "{{{baseName}}}")
+        {{{name}}} = try container.decode{{#required}}{{#isNullable}}IfPresent{{/isNullable}}{{/required}}{{^required}}IfPresent{{/required}}({{{datatypeWithEnum}}}.self, forKey: .{{{name}}})
         {{/allVars}}
         var nonAdditionalPropertyKeys = Set<String>()
         {{#allVars}}
         nonAdditionalPropertyKeys.insert("{{{baseName}}}")
         {{/allVars}}
-        additionalProperties = try container.decodeMap({{{additionalPropertiesType}}}.self, excludedKeys: nonAdditionalPropertyKeys)
+        let additionalPropertiesContainer = try decoder.container(keyedBy: String.self)
+        additionalProperties = try additionalPropertiesContainer.decodeMap({{{additionalPropertiesType}}}.self, excludedKeys: nonAdditionalPropertyKeys)
     }{{/additionalPropertiesType}}{{/generateModelAdditionalProperties}}{{^objcCompatible}}{{#useClasses}}{{#vendorExtensions.x-swift-hashable}}
 
     {{#nonPublicApi}}internal{{/nonPublicApi}}{{^nonPublicApi}}public{{/nonPublicApi}} static func == (lhs: {{classname}}, rhs: {{classname}}) -> Bool {