diff --git a/modules/openapi-generator/src/main/resources/kotlin-client/libraries/jvm-okhttp/api.mustache b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/jvm-okhttp/api.mustache
index bba4a48a002b..bf37a51fd43e 100644
--- a/modules/openapi-generator/src/main/resources/kotlin-client/libraries/jvm-okhttp/api.mustache
+++ b/modules/openapi-generator/src/main/resources/kotlin-client/libraries/jvm-okhttp/api.mustache
@@ -208,17 +208,44 @@ import {{packageName}}.infrastructure.toMultiValue
                 {{#queryParams}}
                 {{^required}}
                 if ({{{paramName}}} != null) {
+                    {{#isModel}}
+                    {{#vars}}
+                    if ({{{paramName}}}.{{name}} != null) {
+                        put("{{#isDeepObject}}{{{paramName}}}[{{/isDeepObject}}{{#lambda.escapeDollar}}{{baseName}}{{/lambda.escapeDollar}}{{#isDeepObject}}]{{/isDeepObject}}", {{#isContainer}}toMultiValue({{{paramName}}}.{{name}}.toList(), "{{collectionFormat}}"){{/isContainer}}{{^isContainer}}listOf({{#isDateTime}}parseDateToQueryString({{{paramName}}}.{{name}}){{/isDateTime}}{{#isDate}}parseDateToQueryString({{{paramName}}}.{{name}}){{/isDate}}{{#isEnum}}{{#isString}}{{{paramName}}}.{{name}}.value{{/isString}}{{^isString}}{{{paramName}}}.{{name}}.toString(){{/isString}}{{/isEnum}}{{^isEnum}}{{^isDateTime}}{{^isDate}}{{{paramName}}}.{{name}}.toString(){{/isDate}}{{/isDateTime}}{{/isEnum}}){{/isContainer}})
+                    }
+                    {{/vars}}
+                    {{/isModel}}
+                    {{^isModel}}
                     put("{{#lambda.escapeDollar}}{{baseName}}{{/lambda.escapeDollar}}", {{#isContainer}}toMultiValue({{{paramName}}}.toList(), "{{collectionFormat}}"){{/isContainer}}{{^isContainer}}listOf({{#isDateTime}}parseDateToQueryString({{{paramName}}}){{/isDateTime}}{{#isDate}}parseDateToQueryString({{{paramName}}}){{/isDate}}{{#isEnum}}{{#isString}}{{{paramName}}}.value{{/isString}}{{^isString}}{{{paramName}}}.toString(){{/isString}}{{/isEnum}}{{^isEnum}}{{^isDateTime}}{{^isDate}}{{{paramName}}}.toString(){{/isDate}}{{/isDateTime}}{{/isEnum}}){{/isContainer}})
+                    {{/isModel}}
                 }
                 {{/required}}
                 {{#required}}
                 {{#isNullable}}
                 if ({{{paramName}}} != null) {
+                    {{#isModel}}
+                    {{#vars}}
+                    if ({{{paramName}}}.{{name}} != null) {
+                        put("{{#isDeepObject}}{{{paramName}}}[{{/isDeepObject}}{{#lambda.escapeDollar}}{{baseName}}{{/lambda.escapeDollar}}{{#isDeepObject}}]{{/isDeepObject}}", {{#isContainer}}toMultiValue({{{paramName}}}.{{name}}.toList(), "{{collectionFormat}}"){{/isContainer}}{{^isContainer}}listOf({{#isDateTime}}parseDateToQueryString({{{paramName}}}.{{name}}){{/isDateTime}}{{#isDate}}parseDateToQueryString({{{paramName}}}.{{name}}){{/isDate}}{{#isEnum}}{{#isString}}{{{paramName}}}.{{name}}.value{{/isString}}{{^isString}}{{{paramName}}}.{{name}}.toString(){{/isString}}{{/isEnum}}{{^isEnum}}{{^isDateTime}}{{^isDate}}{{{paramName}}}.{{name}}.toString(){{/isDate}}{{/isDateTime}}{{/isEnum}}){{/isContainer}})
+                    }
+                    {{/vars}}
+                    {{/isModel}}
+                    {{^isModel}}
                     put("{{#lambda.escapeDollar}}{{baseName}}{{/lambda.escapeDollar}}", {{#isContainer}}toMultiValue({{{paramName}}}.toList(), "{{collectionFormat}}"){{/isContainer}}{{^isContainer}}listOf({{#isDateTime}}parseDateToQueryString({{{paramName}}}){{/isDateTime}}{{#isDate}}parseDateToQueryString({{{paramName}}}){{/isDate}}{{#isEnum}}{{#isString}}{{{paramName}}}.value{{/isString}}{{^isString}}{{{paramName}}}.toString(){{/isString}}{{/isEnum}}{{^isEnum}}{{^isDateTime}}{{^isDate}}{{{paramName}}}.toString(){{/isDate}}{{/isDateTime}}{{/isEnum}}){{/isContainer}})
+                    {{/isModel}}
                 }
                 {{/isNullable}}
                 {{^isNullable}}
+                {{#isModel}}
+                {{#vars}}
+                if ({{{paramName}}}.{{name}} != null) {
+                    put("{{#isDeepObject}}{{{paramName}}}[{{/isDeepObject}}{{#lambda.escapeDollar}}{{baseName}}{{/lambda.escapeDollar}}{{#isDeepObject}}]{{/isDeepObject}}", {{#isContainer}}toMultiValue({{{paramName}}}.{{name}}.toList(), "{{collectionFormat}}"){{/isContainer}}{{^isContainer}}listOf({{#isDateTime}}parseDateToQueryString({{{paramName}}}.{{name}}){{/isDateTime}}{{#isDate}}parseDateToQueryString({{{paramName}}}.{{name}}){{/isDate}}{{#isEnum}}{{#isString}}{{{paramName}}}.{{name}}.value{{/isString}}{{^isString}}{{{paramName}}}.{{name}}.toString(){{/isString}}{{/isEnum}}{{^isEnum}}{{^isDateTime}}{{^isDate}}{{{paramName}}}.{{name}}.toString(){{/isDate}}{{/isDateTime}}{{/isEnum}}){{/isContainer}})
+                }
+                {{/vars}}
+                {{/isModel}}
+                {{^isModel}}
                 put("{{#lambda.escapeDollar}}{{baseName}}{{/lambda.escapeDollar}}", {{#isContainer}}toMultiValue({{{paramName}}}.toList(), "{{collectionFormat}}"){{/isContainer}}{{^isContainer}}listOf({{#isDateTime}}parseDateToQueryString({{{paramName}}}){{/isDateTime}}{{#isDate}}parseDateToQueryString({{{paramName}}}){{/isDate}}{{#isEnum}}{{#isString}}{{{paramName}}}.value{{/isString}}{{^isString}}{{{paramName}}}.toString(){{/isString}}{{/isEnum}}{{^isEnum}}{{^isDateTime}}{{^isDate}}{{{paramName}}}.toString(){{/isDate}}{{/isDateTime}}{{/isEnum}}){{/isContainer}})
+                {{/isModel}}
                 {{/isNullable}}
                 {{/required}}
                 {{/queryParams}}
diff --git a/samples/client/echo_api/kotlin-jvm-okhttp/src/main/kotlin/org/openapitools/client/apis/QueryApi.kt b/samples/client/echo_api/kotlin-jvm-okhttp/src/main/kotlin/org/openapitools/client/apis/QueryApi.kt
index eb54542a355f..1c45b2cba058 100644
--- a/samples/client/echo_api/kotlin-jvm-okhttp/src/main/kotlin/org/openapitools/client/apis/QueryApi.kt
+++ b/samples/client/echo_api/kotlin-jvm-okhttp/src/main/kotlin/org/openapitools/client/apis/QueryApi.kt
@@ -391,7 +391,24 @@ class QueryApi(basePath: kotlin.String = defaultBasePath, client: Call.Factory =
         val localVariableQuery: MultiValueMap = mutableMapOf<kotlin.String, kotlin.collections.List<kotlin.String>>()
             .apply {
                 if (queryObject != null) {
-                    put("query_object", listOf(queryObject.toString()))
+                    if (queryObject.id != null) {
+                        put("queryObject[id]", listOf(queryObject.id.toString()))
+                    }
+                    if (queryObject.name != null) {
+                        put("queryObject[name]", listOf(queryObject.name.toString()))
+                    }
+                    if (queryObject.category != null) {
+                        put("queryObject[category]", listOf(queryObject.category.toString()))
+                    }
+                    if (queryObject.photoUrls != null) {
+                        put("queryObject[photoUrls]", toMultiValue(queryObject.photoUrls.toList(), ""))
+                    }
+                    if (queryObject.tags != null) {
+                        put("queryObject[tags]", toMultiValue(queryObject.tags.toList(), ""))
+                    }
+                    if (queryObject.status != null) {
+                        put("queryObject[status]", listOf(queryObject.status.value))
+                    }
                 }
             }
         val localVariableHeaders: MutableMap<String, String> = mutableMapOf()
@@ -469,7 +486,9 @@ class QueryApi(basePath: kotlin.String = defaultBasePath, client: Call.Factory =
         val localVariableQuery: MultiValueMap = mutableMapOf<kotlin.String, kotlin.collections.List<kotlin.String>>()
             .apply {
                 if (queryObject != null) {
-                    put("query_object", listOf(queryObject.toString()))
+                    if (queryObject.propertyValues != null) {
+                        put("values", toMultiValue(queryObject.propertyValues.toList(), ""))
+                    }
                 }
             }
         val localVariableHeaders: MutableMap<String, String> = mutableMapOf()
@@ -547,7 +566,24 @@ class QueryApi(basePath: kotlin.String = defaultBasePath, client: Call.Factory =
         val localVariableQuery: MultiValueMap = mutableMapOf<kotlin.String, kotlin.collections.List<kotlin.String>>()
             .apply {
                 if (queryObject != null) {
-                    put("query_object", listOf(queryObject.toString()))
+                    if (queryObject.id != null) {
+                        put("id", listOf(queryObject.id.toString()))
+                    }
+                    if (queryObject.name != null) {
+                        put("name", listOf(queryObject.name.toString()))
+                    }
+                    if (queryObject.category != null) {
+                        put("category", listOf(queryObject.category.toString()))
+                    }
+                    if (queryObject.photoUrls != null) {
+                        put("photoUrls", toMultiValue(queryObject.photoUrls.toList(), ""))
+                    }
+                    if (queryObject.tags != null) {
+                        put("tags", toMultiValue(queryObject.tags.toList(), ""))
+                    }
+                    if (queryObject.status != null) {
+                        put("status", listOf(queryObject.status.value))
+                    }
                 }
             }
         val localVariableHeaders: MutableMap<String, String> = mutableMapOf()