diff --git a/bin/bitbake-worker b/bin/bitbake-worker
index 4ad716975..1bde9d261 100755
--- a/bin/bitbake-worker
+++ b/bin/bitbake-worker
@@ -294,8 +294,10 @@ def fork_off_task(cfg, data, databuilder, workerdata, extraconfigdata, runtask):
                     else:
                         logger.debug("Skipping disable network for %s since %s is not a local uid." % (taskname, uid))
 
-                # exported_vars() returns a generator which *cannot* be passed to os.environ.update() 
-                # successfully. We also need to unset anything from the environment which shouldn't be there 
+                # exported_vars() expands each value, so it must be called before
+                # empty_environment() below: an expansion that shells out needs the
+                # environment bitbake was started with. We also need to unset
+                # anything from the environment which shouldn't be there
                 exports = bb.data.exported_vars(the_data)
 
                 bb.utils.empty_environment()
diff --git a/lib/bb/data.py b/lib/bb/data.py
index b12972c03..7c01e6bf8 100644
--- a/lib/bb/data.py
+++ b/lib/bb/data.py
@@ -193,6 +193,12 @@ def exported_keys(d):
                                       not bb.utils.to_boolean(d.getVarFlag(key, 'unexport')))
 
 def exported_vars(d):
+    """Return the exported variables as a list of (key, value) pairs.
+
+    Every value is expanded before returning, so a caller that changes the
+    environment afterwards still gets what the expansion saw.
+    """
+    exported = []
     k = list(exported_keys(d))
     for key in k:
         try:
@@ -202,7 +208,9 @@ def exported_vars(d):
             continue
 
         if value is not None:
-            yield key, str(value)
+            exported.append((key, str(value)))
+
+    return exported
 
 def emit_func(func, o=sys.__stdout__, d = init()):
     """Emits all items in the data store in a format such that it can be sourced by a shell."""
diff --git a/lib/bb/tests/data.py b/lib/bb/tests/data.py
index fd690a9e2..a83c71e2c 100644
--- a/lib/bb/tests/data.py
+++ b/lib/bb/tests/data.py
@@ -723,3 +723,31 @@ class EmitVar(unittest.TestCase):
         self.assertEqual(self.get_output(out), ['bad_chars="a\\"b \\',
                                                 'c\\`d \\',
                                                 'e\\$f"'])
+
+class ExportedVars(unittest.TestCase):
+    def test_expanded_before_returning(self):
+        # Called while the variable is set, read once it is gone: the value
+        # has to be the one from the call, not from the read.
+        d = bb.data.init()
+        d.setVar("TESTVAR", "${@os.environ.get('BB_TEST_EXPORT', 'gone')}")
+        d.setVarFlag("TESTVAR", "export", "1")
+
+        with bb.utils.environment(BB_TEST_EXPORT="present"):
+            exported = bb.data.exported_vars(d)
+
+        self.assertEqual(dict(exported), {"TESTVAR": "present"})
+        self.assertIsInstance(exported, list)
+
+    def test_unexpandable_value_warns_and_is_skipped(self):
+        # The warning belongs to the call, not to a later iteration.
+        d = bb.data.init()
+        d.setVar("TESTVAR", "value")
+        d.setVarFlag("TESTVAR", "export", "1")
+        d.setVar("TESTBROKEN", "${@int('not a number')}")
+        d.setVarFlag("TESTBROKEN", "export", "1")
+
+        with LogRecord() as logs:
+            exported = bb.data.exported_vars(d)
+
+        self.assertEqual(dict(exported), {"TESTVAR": "value"})
+        self.assertTrue(logContains("Unable to export ${TESTBROKEN}", logs))