diff --git a/src/core/components/parameter-row.jsx b/src/core/components/parameter-row.jsx
index 1b10834a..ae12fae9 100644
--- a/src/core/components/parameter-row.jsx
+++ b/src/core/components/parameter-row.jsx
@@ -22,20 +22,7 @@ export default class ParameterRow extends Component {
   constructor(props, context) {
     super(props, context)
 
-    let { specSelectors, pathMethod, param } = props
-    let defaultValue = param.get("default")
-    let xExampleValue = param.get("x-example")
-    let parameter = specSelectors.parameterWithMeta(pathMethod, param.get("name"), param.get("in"))
-    let value = parameter ? parameter.get("value") : ""
-
-    if( param.get("in") !== "body" ) {
-      if ( xExampleValue !== undefined && value === undefined && specSelectors.isSwagger2() ) {
-        this.onChangeWrapper(xExampleValue)
-      } else if ( defaultValue !== undefined && value === undefined ) {
-        this.onChangeWrapper(defaultValue)
-      }
-    }
-
+    this.setDefaultValue()
   }
 
   componentWillReceiveProps(props) {
@@ -43,7 +30,6 @@ export default class ParameterRow extends Component {
     let { isOAS3 } = specSelectors
 
     let example = param.get("example")
-    let defaultValue = param.get("default")
     let parameter = specSelectors.parameterWithMeta(pathMethod, param.get("name"), param.get("in"))
     let enumValue
 
@@ -61,8 +47,6 @@ export default class ParameterRow extends Component {
       value = paramValue
     } else if ( example !== undefined ) {
       value = example
-    } else if ( defaultValue !== undefined) {
-      value = defaultValue
     } else if ( param.get("required") && enumValue && enumValue.size ) {
       value = enumValue.first()
     }
@@ -77,6 +61,29 @@ export default class ParameterRow extends Component {
     return onChange(param, value)
   }
 
+  setDefaultValue = () => {
+    let { specSelectors, pathMethod, param } = this.props
+
+    if (param.get("value") !== undefined) {
+      return
+    }
+
+    let schema = specSelectors.isOAS3() ? param.get("schema", Map({})) : param
+
+    let defaultValue = schema.get("default")
+    let xExampleValue = param.get("x-example") // Swagger 2 only
+    let parameter = specSelectors.parameterWithMeta(pathMethod, param.get("name"), param.get("in"))
+    let value = parameter ? parameter.get("value") : ""
+
+    if( param.get("in") !== "body" ) {
+      if ( xExampleValue !== undefined && value === undefined && specSelectors.isSwagger2() ) {
+        this.onChangeWrapper(xExampleValue)
+      } else if ( defaultValue !== undefined && value === undefined ) {
+        this.onChangeWrapper(defaultValue)
+      }
+    }
+  }
+
   render() {
     let {param, onChange, getComponent, getConfigs, isExecute, fn, onChangeConsumes, specSelectors, pathMethod, specPath} = this.props
 
diff --git a/test/bugs/4557-default-parameter-values.js b/test/bugs/4557-default-parameter-values.js
new file mode 100644
index 00000000..20514678
--- /dev/null
+++ b/test/bugs/4557-default-parameter-values.js
@@ -0,0 +1,67 @@
+/* eslint-env mocha */
+import React from "react"
+import { List, fromJS } from "immutable"
+import expect, { createSpy } from "expect"
+import { render } from "enzyme"
+import ParameterRow from "components/parameter-row"
+
+describe("bug #4557: default parameter values", function(){
+  it("should apply a Swagger 2.0 default value", function(){
+
+    const paramValue = fromJS({
+      description: "a pet",
+      type: "string",
+      default: "MyDefaultValue"
+    })
+
+    let props = {
+      getComponent: ()=> "div",
+      specSelectors: {
+        security(){},
+        parameterWithMeta(){ return paramValue },
+        isOAS3(){ return false }
+      },
+      operation: {get: ()=>{}},
+      onChange: createSpy(),
+      param: paramValue,
+      onChangeConsumes: () => {},
+      pathMethod: [],
+      getConfigs: () => { return {} },
+      specPath: List([])
+    }
+
+    render(<ParameterRow {...props}/>)
+
+    expect(props.onChange).toHaveBeenCalledWith(paramValue, "MyDefaultValue")
+  })
+  it("should apply an OpenAPI 3.0 default value", function(){
+
+    const paramValue = fromJS({
+      description: "a pet",
+      schema: {
+        type: "string",
+        default: "MyDefaultValue"
+      }
+    })
+
+    let props = {
+      getComponent: ()=> "div",
+      specSelectors: {
+        security(){},
+        parameterWithMeta(){ return paramValue },
+        isOAS3(){ return true }
+      },
+      operation: {get: ()=>{}},
+      onChange: createSpy(),
+      param: paramValue,
+      onChangeConsumes: () => {},
+      pathMethod: [],
+      getConfigs: () => { return {} },
+      specPath: List([])
+    }
+
+    render(<ParameterRow {...props}/>)
+
+    expect(props.onChange).toHaveBeenCalledWith(paramValue, "MyDefaultValue")
+  })
+})