diff --git a/AppKit/CPRadio.j b/AppKit/CPRadio.j
index f0c725a7e..a2b6f51d9 100644
--- a/AppKit/CPRadio.j
+++ b/AppKit/CPRadio.j
@@ -67,6 +67,18 @@ CPRadioImageOffset = 4.0;
     [[button1 radioGroup] selectedRadio] returns the currently selected
     option.
 
+    UPDATE 09/2020 : Implementation of modern Cocoa behavior :
+
+    As in Cocoa, radio buttons grouping is now automatic.
+
+    To be associated in a common group (and so being mutually exclusive),
+    radio buttons must combine 2 criteria :
+
+    - same superview (enclosing view)
+    - same action
+
+    TODO: This first implementation uses "as is" CPRadioGroup. This could
+          be simplified (no more need for radio group action, for example)
 */
 @implementation CPRadio : CPButton
 {
@@ -160,6 +172,63 @@ CPRadioImageOffset = 4.0;
         [CPApp sendAction:[_radioGroup action] to:[_radioGroup target] from:_radioGroup];
 }
 
+- (void)viewDidMoveToSuperview
+{
+    [self _setRadioGroup];
+    [super viewDidMoveToSuperview];
+}
+
+- (void)setAction:(SEL)anAction
+{
+    if (anAction === _action)
+        return;
+
+    [super setAction:anAction];
+    [self _setRadioGroup];
+}
+
+#pragma mark Private methods
+
+- (void)_setRadioGroup
+{
+    // Implementation of modern Cocoa behavior : automatic radio group
+
+    // If no action is set or no superview, no grouping can be done.
+    if (![self action] || ![self superview])
+    {
+        // If I'm in a group (size > 1), remove me.
+        if ([[self radioGroup] size] > 1)
+            [self setRadioGroup:[CPRadioGroup new]];
+
+        return;
+    }
+
+    // Search in superview subviews for other radio buttons having the same action.
+    // Take the one with the radio group having the greatest number of members.
+
+    var radioGroup;
+
+    for (var i = 0, superviewSubviews = [[self superview] subviews], count = [superviewSubviews count], aSubview, myAction = [self action], radioGroupSize = -1; (i < count); i++)
+    {
+        aSubview = superviewSubviews[i];
+
+        if ([aSubview isKindOfClass:CPRadio] && (aSubview !== self) && ([aSubview action] === myAction) && ([[aSubview radioGroup] size] > radioGroupSize))
+        {
+            radioGroup     = [aSubview radioGroup];
+            radioGroupSize = [radioGroup size];
+        }
+    }
+
+    if (radioGroup)
+        [self setRadioGroup:radioGroup];
+    else
+        // No other radio buttons to group with found.
+        // It may be because this radio button was in a radio group and its action was changed.
+        // If this is the case, we must reisolate it in a new radio group.
+        if ([_radioGroup size] > 1)
+            [self setRadioGroup:[CPRadioGroup new]];
+}
+
 @end
 
 var CPRadioRadioGroupKey    = @"CPRadioRadioGroupKey";
@@ -320,6 +389,11 @@ var CPRadioRadioGroupKey    = @"CPRadioRadioGroupKey";
     return _radios;
 }
 
+- (int)size
+{
+    return [_radios count];
+}
+
 - (void)setEnabled:(BOOL)enabled
 {
     [_radios makeObjectsPerformSelector:@selector(setEnabled:) withObject:enabled];
diff --git a/Tests/AppKit/CPButtonTest.j b/Tests/AppKit/CPButtonTest.j
index 36efd1247..8a0f92e78 100644
--- a/Tests/AppKit/CPButtonTest.j
+++ b/Tests/AppKit/CPButtonTest.j
@@ -190,6 +190,69 @@
     [self assertTrue:wasClicked message:@"a user click on a radio button should fire the group action"];
 }
 
+- (void)testAutomaticRadioGroup
+{
+    var radioButton1 = [CPRadio radioWithTitle:@"Radio 1"],
+        radioButton2 = [CPRadio radioWithTitle:@"Radio 2"],
+        radioButton3 = [CPRadio radioWithTitle:@"Radio 3"],
+        simpleView1  = [[CPView alloc] initWithFrame:CGRectMakeZero()],
+        simpleView2  = [[CPView alloc] initWithFrame:CGRectMakeZero()];
+
+    // Initially, buttons are isolated
+    [self assertFalse:([radioButton1 radioGroup] === [radioButton2 radioGroup]) message:@"initially, buttons should be isolated"];
+
+    [simpleView1 addSubview:radioButton1];
+    [simpleView1 addSubview:radioButton2];
+
+    // As no actions are defined, buttons are still isolated
+    [self assertFalse:([radioButton1 radioGroup] === [radioButton2 radioGroup]) message:@"no actions defined, buttons should be isolated"];
+
+    [radioButton1 setAction:@selector(dummyAction1:)];
+    [radioButton2 setAction:@selector(dummyAction2:)];
+
+    // As different actions are defined, buttons are still isolatdd
+    [self assertFalse:([radioButton1 radioGroup] === [radioButton2 radioGroup]) message:@"different actions defined, buttons should be isolated"];
+
+    [radioButton2 setAction:@selector(dummyAction1:)];
+
+    // As the same action is defined, buttons must be grouped
+    [self assertTrue:([radioButton1 radioGroup] === [radioButton2 radioGroup]) message:@"same action defined, buttons should be grouped"];
+
+    [radioButton3 setAction:@selector(dummyAction1:)];
+
+    // As radioButton3 is not inserted in a view, it's isolated
+    [self assertTrue:([[radioButton3 radioGroup] size] === 1) message:@"not in a view, button should be isolated"];
+
+    [simpleView2 addSubview:radioButton3];
+
+    // As radioButton3 is in another view, it's isolated from radioButton1 & 2
+    [self assertTrue:([[radioButton3 radioGroup] size] === 1) message:@"alone in a view, button should be isolated"];
+
+    [simpleView1 addSubview:radioButton3];
+
+    // As all 3 buttons are in the same view, with the same action, they are grouped
+    [self assertTrue:([[radioButton3 radioGroup] size] === 3) message:@"after moving to the same view, buttons should be grouped"];
+
+    [radioButton3 setAction:@selector(dummyAction2:)];
+
+    // As the action of button 3 is now different, it's isolated
+    [self assertTrue:([[radioButton3 radioGroup] size] === 1) message:@"after changing the action, button 3 should be isolated"];
+
+    // And buttons 1 & 2 are still grouped
+    [self assertTrue:([radioButton1 radioGroup] === [radioButton2 radioGroup]) message:@"buttons 1 & 2 should remain grouped"];
+    [self assertTrue:([[radioButton1 radioGroup] size] === 2) message:@"radio group should contain only buttons 1 & 2"];
+}
+
+- (IBAction)dummyAction1:(id)sender
+{
+
+}
+
+- (IBAction)dummyAction2:(id)sender
+{
+
+}
+
 - (void)testTypeMasks
 {
     button = [[CPButton alloc] initWithFrame:CGRectMakeZero()];