diff --git a/fdbclient/FDBTypes.h b/fdbclient/FDBTypes.h
index 06b574ec89..690ebb9865 100644
--- a/fdbclient/FDBTypes.h
+++ b/fdbclient/FDBTypes.h
@@ -331,12 +331,12 @@ struct string_serialized_traits<KeyValueRef> : std::true_type {
 	uint32_t save(uint8_t* out, const KeyValueRef& item) const {
 		auto begin = out;
 		uint32_t sz = item.key.size();
-		memcpy(out, &sz, sizeof(sz));
+		*reinterpret_cast<decltype(sz)*>(out) = sz;
 		out += sizeof(sz);
 		memcpy(out, item.key.begin(), sz);
 		out += sz;
 		sz = item.value.size();
-		memcpy(out, &sz, sizeof(sz));
+		*reinterpret_cast<decltype(sz)*>(out) = sz;
 		out += sizeof(sz);
 		memcpy(out, item.value.begin(), sz);
 		out += sz;
diff --git a/flow/Arena.h b/flow/Arena.h
index b956b195b0..0f78d41290 100644
--- a/flow/Arena.h
+++ b/flow/Arena.h
@@ -1143,7 +1143,7 @@ struct dynamic_size_traits<VectorRef<V, VecSerStrategy::String>> : std::true_typ
 		string_serialized_traits<V> traits;
 		auto* p = out;
 		uint32_t length = t.size();
-		memcpy(out, &length, sizeof(length));
+		*reinterpret_cast<decltype(length)*>(out) = length;
 		out += sizeof(length);
 		for (const auto& item : t) {
 			out += traits.save(out, item);