diff --git a/test/packetmath.cpp b/test/packetmath.cpp
index 5e4d6f0d3..9564bc283 100644
--- a/test/packetmath.cpp
+++ b/test/packetmath.cpp
@@ -43,7 +43,8 @@ T apply_bit_op(Bits a, Bits b, Func f) {
   T res;
   for(Index i = 0; i < data.size(); ++i)
     data[i] = f(a[i], b[i]);
-  std::memcpy(&res, &data, sizeof(T));
+  // Note: The reinterpret_cast works around GCC's class-memaccess warnings:
+  std::memcpy(reinterpret_cast<unsigned char*>(&res), &data, sizeof(T));
   return res;
 }