diff --git a/cpp/src/datetime/datetime_ops.cu b/cpp/src/datetime/datetime_ops.cu
index c5fcb7d1af0..041162c7034 100644
--- a/cpp/src/datetime/datetime_ops.cu
+++ b/cpp/src/datetime/datetime_ops.cu
@@ -105,7 +105,7 @@ struct ceil_timestamp {
         return time_point_cast<typename Timestamp::duration>(ceil<duration_us>(ts));
       case datetime_component::NANOSECOND:
         return time_point_cast<typename Timestamp::duration>(ceil<duration_ns>(ts));
-      default: return time_point_cast<typename Timestamp::duration>(ceil<duration_s>(ts));
+      default: cudf_assert(false && "Unexpected resolution"); ;
     }
   }
 };