diff --git a/llvm/include/llvm/ADT/APFloat.h b/llvm/include/llvm/ADT/APFloat.h
index 6bc62845fddf4..a1bfce7d1bd5a 100644
--- a/llvm/include/llvm/ADT/APFloat.h
+++ b/llvm/include/llvm/ADT/APFloat.h
@@ -1313,7 +1313,7 @@ class APFloat : public APFloatBase {
 
   /// Assuming this is an IEEE-754 NaN value, quiet its signaling bit.
   /// This preserves the sign and payload bits.
-  APFloat makeQuiet() const {
+  [[nodiscard]] APFloat makeQuiet() const {
     APFloat Result(*this);
     Result.getIEEE().makeQuiet();
     return Result;