diff --git a/bitbake/lib/bb/data_smart.py b/bitbake/lib/bb/data_smart.py
index ca5774b26b..66cb84564e 100644
--- a/bitbake/lib/bb/data_smart.py
+++ b/bitbake/lib/bb/data_smart.py
@@ -384,7 +384,12 @@ class DataSmart(MutableMapping):
             olds = s
             try:
                 s = __expand_var_regexp__.sub(varparse.var_sub, s)
-                s = __expand_python_regexp__.sub(varparse.python_sub, s)
+                try:
+                    s = __expand_python_regexp__.sub(varparse.python_sub, s)
+                except SyntaxError as e:
+                    # Likely unmatched brackets, just don't expand the expression
+                    if e.msg != "EOL while scanning string literal":
+                        raise
                 if s == olds:
                     break
             except ExpansionError:
diff --git a/bitbake/lib/bb/tests/data.py b/bitbake/lib/bb/tests/data.py
index e9aab577f6..a96078fa9c 100644
--- a/bitbake/lib/bb/tests/data.py
+++ b/bitbake/lib/bb/tests/data.py
@@ -80,6 +80,11 @@ class DataExpansions(unittest.TestCase):
         val = self.d.expand("${@d.getVar('foo', True) + ' ${bar}'}")
         self.assertEqual(str(val), "value_of_foo value_of_bar")
 
+    def test_python_unexpanded(self):
+        self.d.setVar("bar", "${unsetvar}")
+        val = self.d.expand("${@d.getVar('foo', True) + ' ${bar}'}")
+        self.assertEqual(str(val), "${@d.getVar('foo', True) + ' ${unsetvar}'}")
+
     def test_python_snippet_syntax_error(self):
         self.d.setVar("FOO", "${@foo = 5}")
         self.assertRaises(bb.data_smart.ExpansionError, self.d.getVar, "FOO", True)