diff --git a/CHANGELOG.md b/CHANGELOG.md
index 68328b17e7..e5ee777493 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,9 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 
 ## [UNRELEASED]
 
+## Breaking
+- [#2450](https://github.com/plotly/dash/pull/2450) Set label style `display: block` if `inline` is false in RadioItems & Checklist components. To keep previous behavior, set `inline=True`. This is already how it was described and worked in our documentation and other places with CSS stylesheets that set the default orientation of RadioItems and Checklist options to vertical (including Dash Design Kit), but for unstyled pages it is a breaking change.
+
 ## Added
 
 - [#2068](https://github.com/plotly/dash/pull/2068) Added `refresh="callback-nav"` in `dcc.Location`. This allows for navigation without refreshing the page when url is updated in a callback.
diff --git a/components/dash-core-components/src/components/Checklist.react.js b/components/dash-core-components/src/components/Checklist.react.js
index b911612a2b..784d8fc596 100644
--- a/components/dash-core-components/src/components/Checklist.react.js
+++ b/components/dash-core-components/src/components/Checklist.react.js
@@ -38,11 +38,10 @@ export default class Checklist extends Component {
                     return (
                         <label
                             key={option.value}
-                            style={Object.assign(
-                                {},
-                                labelStyle,
-                                inline ? {display: 'inline-block'} : {}
-                            )}
+                            style={{
+                                display: inline ? 'inline-block' : 'block',
+                                ...labelStyle,
+                            }}
                             className={labelClassName}
                         >
                             <input
@@ -144,9 +143,8 @@ Checklist.propTypes = {
     ),
 
     /**
-     * Indicates whether labelStyle should be inline or not
-     * True: Automatically set { 'display': 'inline-block' } to labelStyle
-     * False: No additional styles are passed into labelStyle.
+     * Indicates whether the options labels should be displayed inline (true=horizontal)
+     * or in a block (false=vertical).
      */
     inline: PropTypes.bool,
 
diff --git a/components/dash-core-components/src/components/RadioItems.react.js b/components/dash-core-components/src/components/RadioItems.react.js
index a8c968e53d..a62e2293ff 100644
--- a/components/dash-core-components/src/components/RadioItems.react.js
+++ b/components/dash-core-components/src/components/RadioItems.react.js
@@ -42,11 +42,10 @@ export default class RadioItems extends Component {
             >
                 {sanitizeOptions(options).map(option => (
                     <label
-                        style={Object.assign(
-                            {},
-                            labelStyle,
-                            inline ? {display: 'inline-block'} : {}
-                        )}
+                        style={{
+                            display: inline ? 'inline-block' : 'block',
+                            ...labelStyle,
+                        }}
                         className={labelClassName}
                         key={option.value}
                     >
@@ -137,9 +136,8 @@ RadioItems.propTypes = {
     ]),
 
     /**
-     * Indicates whether labelStyle should be inline or not
-     * True: Automatically set { 'display': 'inline-block' } to labelStyle
-     * False: No additional styles are passed into labelStyle.
+     * Indicates whether the options labels should be displayed inline (true=horizontal)
+     * or in a block (false=vertical).
      */
     inline: PropTypes.bool,
 
diff --git a/components/dash-core-components/tests/test_inline.py b/components/dash-core-components/tests/test_inline.py
new file mode 100644
index 0000000000..ea7ef59c69
--- /dev/null
+++ b/components/dash-core-components/tests/test_inline.py
@@ -0,0 +1,22 @@
+from dash import Dash, html, dcc
+
+
+def test_inline_props(dash_dcc):
+    app = Dash(__name__)
+
+    options = ["one", "two", "three"]
+    app.layout = html.Div(
+        [
+            html.Div(
+                [
+                    html.H2(f"Inline: {inline}"),
+                    dcc.RadioItems(options=options, inline=inline),
+                    dcc.Checklist(options=options, inline=inline),
+                ]
+            )
+            for inline in [True, False]
+        ]
+    )
+
+    dash_dcc.start_server(app)
+    dash_dcc.percy_snapshot("RadioItems/Checklist-inline")