diff --git a/modules/openapi-generator/src/main/resources/JavaVertXWebServer/queryParams.mustache b/modules/openapi-generator/src/main/resources/JavaVertXWebServer/queryParams.mustache
index 70a41051955..5da5fc9f654 100644
--- a/modules/openapi-generator/src/main/resources/JavaVertXWebServer/queryParams.mustache
+++ b/modules/openapi-generator/src/main/resources/JavaVertXWebServer/queryParams.mustache
@@ -4,7 +4,7 @@
         {{{dataType}}} {{paramName}} = requestParameters.queryParameter("{{baseName}}") != null ? DatabindCodec.mapper().convertValue(requestParameters.queryParameter("{{baseName}}").get(), new TypeReference<{{{dataType}}}>(){}) : null;
 {{/isModel}}
 {{^isModel}}
-        {{{dataType}}} {{paramName}} = requestParameters.queryParameter("{{baseName}}") != null ? requestParameters.queryParameter("{{baseName}}").get{{dataType}}() : null;
+        {{{dataType}}} {{paramName}} = requestParameters.queryParameter("{{baseName}}") != null ? requestParameters.queryParameter("{{baseName}}").get{{dataType}}() : {{^defaultValue}}null{{/defaultValue}}{{#defaultValue}}{{#isString}}{{#isEnum}}"{{/isEnum}}{{.}}{{#isEnum}}"{{/isEnum}}{{/isString}}{{#isBoolean}}{{.}}{{/isBoolean}}{{#isLong}}{{.}}L{{/isLong}}{{^isLong}}{{#isInteger}}{{.}}{{/isInteger}}{{^isInteger}}{{#isShort}}{{.}}{{/isShort}}{{/isInteger}}{{/isLong}}{{/defaultValue}};
 {{/isModel}}
 {{/isArray}}
 {{#isArray}}