diff --git a/_pytest/python.py b/_pytest/python.py
index 8ce12efb3..5b4f0b62c 100644
--- a/_pytest/python.py
+++ b/_pytest/python.py
@@ -1626,18 +1626,18 @@ class FixtureManager:
                                     unittest=unittest)
             faclist = self._arg2fixturedefs.setdefault(name, [])
             if not fixturedef.has_location:
-                # All Nones are at the front so this inserts the
-                # current fixturedef after the existing fixturedefs
-                # from external plugins but before the fixturedefs
-                # provided in conftests.
-                i = faclist.count(None)
+                # All fixturedefs with no location are at the front
+                # so this inserts the current fixturedef after the
+                # existing fixturedefs from external plugins but
+                # before the fixturedefs provided in conftests.
+                i = len([f for f in faclist if not f.has_location])
             else:
                 i = len(faclist)  # append
             faclist.insert(i, fixturedef)
             if marker.autouse:
                 autousenames.append(name)
         if autousenames:
-            self._nodeid_and_autousenames.append((nodeid, autousenames))
+            self._nodeid_and_autousenames.append((nodeid or '', autousenames))
 
     def getfixturedefs(self, argname, nodeid):
         try:
diff --git a/testing/python/fixture.py b/testing/python/fixture.py
index 6798da0a9..803e7ac45 100644
--- a/testing/python/fixture.py
+++ b/testing/python/fixture.py
@@ -173,7 +173,7 @@ class TestFillFixtures:
         result = testdir.runpytest(testfile)
         result.stdout.fnmatch_lines(["*1 passed*"])
 
-    def test_extend_fixture_conftest_plugin(request, testdir):
+    def test_extend_fixture_conftest_plugin(self, testdir):
         testdir.makepyfile(testplugin="""
             import pytest
 
@@ -198,6 +198,52 @@ class TestFillFixtures:
         result = testdir.runpytest('-s')
         assert result.ret == 0
 
+    def test_extend_fixture_plugin_plugin(self, testdir):
+        # Two plugins should extend each order in loading order
+        testdir.makepyfile(testplugin0="""
+            import pytest
+
+            @pytest.fixture
+            def foo():
+                return 7
+        """)
+        testdir.makepyfile(testplugin1="""
+            import pytest
+
+            @pytest.fixture
+            def foo(foo):
+                return foo + 7
+        """)
+        testdir.syspathinsert()
+        testdir.makepyfile("""
+            pytest_plugins = ['testplugin0', 'testplugin1']
+
+            def test_foo(foo):
+                assert foo == 14
+        """)
+        result = testdir.runpytest()
+        assert result.ret == 0
+
+    def test_autouse_fixture_plugin(self, testdir):
+        # A fixture from a plugin has no baseid set, which screwed up
+        # the autouse fixture handling.
+        testdir.makepyfile(testplugin="""
+            import pytest
+
+            @pytest.fixture(autouse=True)
+            def foo(request):
+                request.function.foo = 7
+        """)
+        testdir.syspathinsert()
+        testdir.makepyfile("""
+            pytest_plugins = 'testplugin'
+
+            def test_foo(request):
+                assert request.function.foo == 7
+        """)
+        result = testdir.runpytest()
+        assert result.ret == 0
+
     def test_funcarg_lookup_error(self, testdir):
         p = testdir.makepyfile("""
             def test_lookup_error(unknown):