diff --git a/netbox/extras/api/mixins.py b/netbox/extras/api/mixins.py
index 91d1add0b..795d50af8 100644
--- a/netbox/extras/api/mixins.py
+++ b/netbox/extras/api/mixins.py
@@ -45,10 +45,10 @@ class ConfigTemplateRenderMixin:
         try:
             output = configtemplate.render(context=context)
         except Exception as e:
-            return Response(
-                {'detail': configtemplate.format_render_error(e)},
-                status=HTTP_500_INTERNAL_SERVER_ERROR,
-            )
+            detail = configtemplate.format_render_error(e)
+            if request.accepted_renderer.format == 'txt':
+                return Response(detail, status=HTTP_500_INTERNAL_SERVER_ERROR)
+            return Response({'detail': detail}, status=HTTP_500_INTERNAL_SERVER_ERROR)
 
         # If the client has requested "text/plain", return the raw content.
         if request.accepted_renderer.format == 'txt':
diff --git a/netbox/extras/models/configs.py b/netbox/extras/models/configs.py
index 9f028fc61..477fa2e03 100644
--- a/netbox/extras/models/configs.py
+++ b/netbox/extras/models/configs.py
@@ -313,12 +313,11 @@ class ConfigTemplate(
     def format_render_error(self, exc):
         """
         Return a formatted error string for a rendering exception. When debug is enabled, the full
-        traceback is returned. Otherwise, a concise, user-facing message is returned.
-
-        Must be called from within the except block so that traceback.format_exc() is valid.
+        traceback for the provided exception is returned. Otherwise, a concise, user-facing message
+        is returned.
         """
         if self.debug:
-            return traceback.format_exc()
+            return ''.join(traceback.format_exception(exc))
         if isinstance(exc, TemplateError):
             parts = [f"{type(exc).__name__}: {exc}"]
             if getattr(exc, 'name', None):