diff --git a/src/KOKKOS/compute_temp_kokkos.h b/src/KOKKOS/compute_temp_kokkos.h
index 2bb0f9cbb2ce11a63fa6f154fbce30446ba12019..a01bb42f8c3472d8254cb0ecd0e10bcd68461ceb 100644
--- a/src/KOKKOS/compute_temp_kokkos.h
+++ b/src/KOKKOS/compute_temp_kokkos.h
@@ -45,14 +45,13 @@ namespace LAMMPS_NS {
     }
 
     KOKKOS_INLINE_FUNCTION
-    volatile s_CTEMP& operator+=(const volatile s_CTEMP &rhs) volatile {
+    void operator+=(const volatile s_CTEMP &rhs) volatile {
       t0 += rhs.t0;
       t1 += rhs.t1;
       t2 += rhs.t2;
       t3 += rhs.t3;
       t4 += rhs.t4;
       t5 += rhs.t5;
-      return *this;
     }
   };
   typedef s_CTEMP CTEMP;