diff --git a/lti/adapters.py b/lti/adapters.py
index 5a41dd9d..4c891e98 100644
--- a/lti/adapters.py
+++ b/lti/adapters.py
@@ -229,8 +229,12 @@ class DjangoToolConfig(ToolConfAbstract):
 
         # Set tool's private key for signing (e.g., Deep Linking responses)
         key_obj = LTIToolKeys.get_or_create_keys()
-        # Pass the full JWK dict (includes kid) - PyLTI1p3 will handle conversion
-        registration.set_tool_private_key(key_obj.private_key_jwk)
+        jwk_obj = jwk.JWK(**key_obj.private_key_jwk)
+        pem_bytes = jwk_obj.export_to_pem(private_key=True, password=None)
+
+        # Set both the key and kid directly on Registration internal attributes
+        registration._tool_private_key = pem_bytes.decode('utf-8')
+        registration._tool_private_key_kid = key_obj.private_key_jwk['kid']
 
         return registration
 
@@ -255,8 +259,12 @@ class DjangoToolConfig(ToolConfAbstract):
 
         # Set tool's private key for signing (e.g., Deep Linking responses)
         key_obj = LTIToolKeys.get_or_create_keys()
-        # Pass the full JWK dict (includes kid) - PyLTI1p3 will handle conversion
-        registration.set_tool_private_key(key_obj.private_key_jwk)
+        jwk_obj = jwk.JWK(**key_obj.private_key_jwk)
+        pem_bytes = jwk_obj.export_to_pem(private_key=True, password=None)
+
+        # Set both the key and kid directly on Registration internal attributes
+        registration._tool_private_key = pem_bytes.decode('utf-8')
+        registration._tool_private_key_kid = key_obj.private_key_jwk['kid']
 
         return registration
 
diff --git a/lti/deep_linking.py b/lti/deep_linking.py
index bebb12b9..f60c63b3 100644
--- a/lti/deep_linking.py
+++ b/lti/deep_linking.py
@@ -144,8 +144,8 @@ class SelectMediaView(View):
             # Get deep linking settings from original launch data
             deep_linking_settings = message_launch_data.get('https://purl.imsglobal.org/spec/lti-dl/claim/deep_linking_settings', {})
 
-            # Create DeepLink instance directly
-            deep_link = DeepLink(registration, deployment_id, deep_linking_settings)
+            # Create DeepLink instance with tool_config for key retrieval
+            deep_link = DeepLink(registration, deployment_id, deep_linking_settings, tool_config=tool_config)
 
             # Convert content_items to DeepLinkResource objects
             resources = []