diff --git a/lib/Twig/Parser.php b/lib/Twig/Parser.php
index 86bd494f0..62a2cea57 100644
--- a/lib/Twig/Parser.php
+++ b/lib/Twig/Parser.php
@@ -373,10 +373,10 @@ class Twig_Parser implements Twig_ParserInterface
             (!$node instanceof Twig_Node_Text && !$node instanceof Twig_Node_BlockReference && $node instanceof Twig_NodeOutputInterface)
         ) {
             if (false !== strpos((string) $node, chr(0xEF).chr(0xBB).chr(0xBF))) {
-                throw new Twig_Error_Syntax('A template that extends another one cannot have a body but a byte order mark (BOM) has been detected; it must be removed.', $node->getLine(), $this->getFilename());
+                throw new Twig_Error_Syntax('A template that extends another one cannot start with a byte order mark (BOM); it must be removed', $node->getLine(), $this->getFilename());
             }
 
-            throw new Twig_Error_Syntax('A template that extends another one cannot have a body.', $node->getLine(), $this->getFilename());
+            throw new Twig_Error_Syntax('A template that extends another one cannot include contents outside Twig blocks. Did you forget to put the contents inside a {% block %} tag.', $node->getLine(), $this->getFilename());
         }
 
         // bypass "set" nodes as they "capture" the output
diff --git a/test/Twig/Tests/Fixtures/exceptions/child_contents_outside_blocks.test b/test/Twig/Tests/Fixtures/exceptions/child_contents_outside_blocks.test
new file mode 100644
index 000000000..8f94aa30a
--- /dev/null
+++ b/test/Twig/Tests/Fixtures/exceptions/child_contents_outside_blocks.test
@@ -0,0 +1,15 @@
+--TEST--
+Exception for child templates defining contents outside blocks defined by parent
+--TEMPLATE--
+{% extends 'base.twig' %}
+
+Content outside a block.
+
+{% block sidebar %}
+    Content inside a block.
+{% endblock %}
+--TEMPLATE(base.twig)--
+{% block sidebar %}
+{% endblock %}
+--EXCEPTION--
+Twig_Error_Syntax: A template that extends another one cannot include contents outside Twig blocks. Did you forget to put the contents inside a {% block %} tag in "index.twig" at line 3.
diff --git a/test/Twig/Tests/ParserTest.php b/test/Twig/Tests/ParserTest.php
index 8f6831b97..afea63d54 100644
--- a/test/Twig/Tests/ParserTest.php
+++ b/test/Twig/Tests/ParserTest.php
@@ -100,7 +100,7 @@ class Twig_Tests_ParserTest extends PHPUnit_Framework_TestCase
 
     /**
      * @expectedException Twig_Error_Syntax
-     * @expectedExceptionMessage A template that extends another one cannot have a body but a byte order mark (BOM) has been detected; it must be removed at line 1.
+     * @expectedExceptionMessage A template that extends another one cannot start with a byte order mark (BOM); it must be removed at line 1
      */
     public function testFilterBodyNodesWithBOM()
     {