diff --git a/src/editor.js b/src/editor.js
index cd7a8933d..0202c26e1 100644
--- a/src/editor.js
+++ b/src/editor.js
@@ -368,6 +368,12 @@ JSONEditor.AbstractEditor = Class.extend({
   isEnabled: function() {
     return !this.disabled;
   },
+  isRequired: function() {
+    if(typeof this.schema.required === "boolean") return this.schema.required;
+    else if(this.parent && this.parent.schema && Array.isArray(this.parent.schema.required)) return this.parent.schema.required.indexOf(this.key) > -1;
+    else if(this.jsoneditor.options.required_by_default) return true;
+    else return false;
+  },  
   getDisplayText: function(arr) {
     var disp = [];
     var used = {};
diff --git a/src/editors/select.js b/src/editors/select.js
index fe047f297..061a7626a 100644
--- a/src/editors/select.js
+++ b/src/editors/select.js
@@ -68,12 +68,26 @@ JSONEditor.defaults.editors.select = JSONEditor.AbstractEditor.extend({
         self.enum_display[i] = ""+(display[i] || option);
         self.enum_values[i] = self.typecast(option);
       });
+
+      if(!this.isRequired()){
+        self.enum_display.unshift(' ');
+        self.enum_options.unshift('undefined');
+        self.enum_values.unshift(undefined);
+      }
+            
     }
     // Boolean
     else if(this.schema.type === "boolean") {
       self.enum_display = this.schema.options && this.schema.options.enum_titles || ['true','false'];
       self.enum_options = ['1',''];
       self.enum_values = [true,false];
+      
+      if(!this.isRequired()){
+        self.enum_display.unshift(' ');
+        self.enum_options.unshift('undefined');
+        self.enum_values.unshift(undefined);
+      }
+    
     }
     // Dynamic Enum
     else if(this.schema.enumSource) {