diff --git a/_pytest/assertion/__init__.py b/_pytest/assertion/__init__.py
index fdc279387..c6039a0ec 100644
--- a/_pytest/assertion/__init__.py
+++ b/_pytest/assertion/__init__.py
@@ -60,7 +60,7 @@ def pytest_configure(config):
 
 def pytest_unconfigure(config):
     hook = config._assertstate.hook
-    if hook is not None:
+    if hook is not None and hook in sys.meta_path:
         sys.meta_path.remove(hook)
 
 def pytest_collection(session):
diff --git a/testing/test_assertrewrite.py b/testing/test_assertrewrite.py
index 121121fb8..06288e899 100644
--- a/testing/test_assertrewrite.py
+++ b/testing/test_assertrewrite.py
@@ -482,6 +482,12 @@ def test_rewritten():
     assert "@py_builtins" in globals()""".replace("\n", "\r\n"), "wb")
         assert testdir.runpytest().ret == 0
 
+    def test_sys_meta_path_munged(self, testdir):
+        testdir.makepyfile("""
+            def test_meta_path():
+                import sys; sys.meta_path = []""")
+        assert testdir.runpytest().ret == 0
+
     def test_write_pyc(self, testdir, tmpdir, monkeypatch):
         from _pytest.assertion.rewrite import _write_pyc
         from _pytest.assertion import AssertionState