diff --git a/sentry_sdk/integrations/__init__.py b/sentry_sdk/integrations/__init__.py
index 0fe958d217..38af2e7bdb 100644
--- a/sentry_sdk/integrations/__init__.py
+++ b/sentry_sdk/integrations/__init__.py
@@ -144,8 +144,14 @@ def setup_integrations(
                     logger.debug(
                         "Did not enable default integration %s: %s", identifier, e
                     )
-
-                _installed_integrations.add(identifier)
+                else:
+                    _installed_integrations.add(identifier)
+
+    integrations = {
+        identifier: integration
+        for identifier, integration in iteritems(integrations)
+        if identifier in _installed_integrations
+    }
 
     for identifier in integrations:
         logger.debug("Enabling integration %s", identifier)
diff --git a/tests/test_basics.py b/tests/test_basics.py
index b2b8846eb9..5a7be44a8e 100644
--- a/tests/test_basics.py
+++ b/tests/test_basics.py
@@ -59,8 +59,8 @@ def test_auto_enabling_integrations_catches_import_error(sentry_init, caplog):
     sentry_init(auto_enabling_integrations=True, debug=True)
 
     for import_string in _AUTO_ENABLING_INTEGRATIONS:
-        # Ignore redis in the test case, because it is installed as a
-        # dependency for running tests, and therefore always enabled.
+        # Ignore redis in the test case, because it does not raise a DidNotEnable
+        # exception on import; rather, it raises the exception upon enabling.
         if _AUTO_ENABLING_INTEGRATIONS[redis_index] == import_string:
             continue