diff --git a/sycl/include/sycl/ext/oneapi/bfloat16.hpp b/sycl/include/sycl/ext/oneapi/bfloat16.hpp
index 70b96a3976d39..18f53a41b0a5f 100644
--- a/sycl/include/sycl/ext/oneapi/bfloat16.hpp
+++ b/sycl/include/sycl/ext/oneapi/bfloat16.hpp
@@ -182,7 +182,7 @@ class bfloat16 {
   explicit operator bool() { return to_float(value) != 0.0f; }
 
   // Unary minus operator overloading
-  friend bfloat16 operator-(bfloat16 &lhs) {
+  friend bfloat16 operator-(const bfloat16 &lhs) {
 #if defined(__SYCL_DEVICE_ONLY__) && defined(__NVPTX__) &&                     \
     (__SYCL_CUDA_ARCH__ >= 800)
     detail::Bfloat16StorageT res;