diff --git a/src/_zkapauthorizer/tests/test_client_resource.py b/src/_zkapauthorizer/tests/test_client_resource.py
index 09e1bf0f527bc7b80ebda5143f8097c8e48334b3..e420b676f2171f804c989b9e183bce831250dd97 100644
--- a/src/_zkapauthorizer/tests/test_client_resource.py
+++ b/src/_zkapauthorizer/tests/test_client_resource.py
@@ -193,32 +193,6 @@ from .json import (
 
 TRANSIENT_ERROR = u"something went wrong, who knows what"
 
-def get_dummyredeemer_public_key(plugin_name, node_config):
-    """
-    Get the issuer public key a ``DummyRedeemer`` has been configured with.
-
-    :param unicode plugin_name: The plugin name to use to choose a
-        configuration section.
-
-    :param _Config node_config: See ``from_configuration``.
-    """
-    section_name = u"storageclient.plugins.{}".format(plugin_name)
-    redeemer_kind = node_config.get_config(
-        section=section_name,
-        option=u"redeemer",
-    )
-    if redeemer_kind != "dummy":
-        raise ValueError(
-            "Cannot read dummy redeemer public key from configuration for {!r} redeemer.".format(
-                redeemer_kind,
-            ),
-        )
-    return node_config.get_config(
-        section=section_name,
-        option=u"issuer-public-key",
-    ).decode("utf-8")
-
-
 # Helper to work-around https://github.com/twisted/treq/issues/161
 def uncooperator(started=True):
     return Cooperator(