diff --git a/xla/stream_executor/device_description.h b/xla/stream_executor/device_description.h
index 313ae5e2dca5e..f6bb2e4a41ad4 100644
--- a/xla/stream_executor/device_description.h
+++ b/xla/stream_executor/device_description.h
@@ -342,7 +342,7 @@ class DeviceDescription {
   }
 
   // Returns the number of threads per warp/wavefront.
-  const int64_t &threads_per_warp() const { return threads_per_warp_; }
+  constexpr int64_t threads_per_warp() const { return threads_per_warp_; }
 
   // Returns the limit on the total number of registers per core.
   const int64_t &registers_per_core_limit() const {