diff --git a/nova/conf/cache.py b/nova/conf/cache.py
index cccabf7d7d96..775368ec2198 100644
--- a/nova/conf/cache.py
+++ b/nova/conf/cache.py
@@ -23,4 +23,5 @@ def register_opts(conf):
 
 
 def list_opts():
-    return core._opts.list_opts()
+    # The oslo_cache library returns a list of tuples
+    return dict(core._opts.list_opts())
diff --git a/nova/conf/opts.py b/nova/conf/opts.py
index 1bb5dcc0dc04..9aed6b28c234 100644
--- a/nova/conf/opts.py
+++ b/nova/conf/opts.py
@@ -72,19 +72,8 @@ def _import_modules(module_names):
     return imported_modules
 
 
-def _process_old_opts(configs):
-    """Convert old-style 2-tuple configs to dicts."""
-    if isinstance(configs, tuple):
-        configs = [configs]
-    return {label: options for label, options in configs}
-
-
 def _append_config_options(imported_modules, config_options):
     for mod in imported_modules:
         configs = mod.list_opts()
-        # TODO(markus_z): Remove this compatibility shim once all list_opts()
-        # functions have been updated to return dicts.
-        if not isinstance(configs, dict):
-            configs = _process_old_opts(configs)
         for key, val in configs.items():
             config_options[key].extend(val)
diff --git a/nova/conf/ssl.py b/nova/conf/ssl.py
index d0370ce0c1de..8d59ae653220 100644
--- a/nova/conf/ssl.py
+++ b/nova/conf/ssl.py
@@ -21,4 +21,5 @@ def register_opts(conf):
 
 
 def list_opts():
-    return sslutils.list_opts()
+    # The oslo_cache library returns a list of tuples
+    return dict(sslutils.list_opts())