diff --git a/hpvm/include/hpvm.h b/hpvm/include/hpvm.h
index 9e2e6bc36e488a0d3e61bf0e2e8171bdce064115..f76dde028e61d2c940a15fc34e1dda10431a06b8 100644
--- a/hpvm/include/hpvm.h
+++ b/hpvm/include/hpvm.h
@@ -6,6 +6,8 @@
  *cr
  ***************************************************************************/
 
+// This changes hpvm::DEVICE (backward-compatible hint name) to hpvm::CUDNN_TARGET.
+// hpvm::DEVICE is deprecated; do not use.
 #ifndef DEVICE
 #define DEVICE CUDNN_TARGET
 #endif