diff --git a/fields/__init__.py b/fields/__init__.py
index a10ccc8..2dab81b 100644
--- a/fields/__init__.py
+++ b/fields/__init__.py
@@ -467,6 +467,15 @@ class Field:
         self.hasHelp  = self.hasLayoutElement('h', layouts)
         return layouts
 
+    @staticmethod
+    def copyLayouts(layouts):
+        '''Create a deep copy of p_layouts.'''
+        res = {}
+        for k, v in layouts.iteritems():
+            if isinstance(v, Table): res[k] = Table(other=v)
+            else: res[k] = v
+        return res
+
     def hasLayoutElement(self, element, layouts):
         '''This method returns True if the given layout p_element can be found
            at least once among the various p_layouts defined for this field.'''
diff --git a/fields/boolean.py b/fields/boolean.py
index 043d30b..e6acf64 100644
--- a/fields/boolean.py
+++ b/fields/boolean.py
@@ -27,7 +27,7 @@ class Boolean(Field):
     trueFalse = {True: 'true', False: 'false'}
 
     # Default layout (render = "checkbox") ("b" stands for "base").
-    bLayouts = {'view': 'lf', 'edit': Table('f;lrv;=', width=None),
+    bLayouts = {'view': 'lf', 'edit': Table('f;lrv;-', width=None),
                 'search': 'l-f'}
     # Layout including a description.
     dLayouts = {'view': 'lf', 'edit': Table('flrv;=d', width=None)}
@@ -97,7 +97,9 @@ class Boolean(Field):
         self.pythonType = bool
 
     def getDefaultLayouts(self):
-        return (self.render == 'radios') and self.rLayouts or self.bLayouts
+        cp = Field.copyLayouts
+        if self.render == 'radios': return cp(Boolean.rLayouts)
+        return cp(Boolean.bLayouts)
 
     def getValue(self, obj):
         '''Never returns "None". Returns always "True" or "False", even if