diff --git a/alternator/executor.cc b/alternator/executor.cc
index 7a95a4efa0..2fa795ec8c 100644
--- a/alternator/executor.cc
+++ b/alternator/executor.cc
@@ -958,21 +958,6 @@ static std::string get_item_type_string(const rjson::value& v) {
     return it->name.GetString();
 }
 
-// Check if a given JSON object encodes a set (i.e., it is a {"SS": [...]}, or "NS", "BS"
-// and returns set's type and a pointer to that set. If the object does not encode a set,
-// returned value is {"", nullptr}
-static const std::pair<std::string, const rjson::value*> unwrap_set(const rjson::value& v) {
-    if (!v.IsObject() || v.MemberCount() != 1) {
-        return {"", nullptr};
-    }
-    auto it = v.MemberBegin();
-    const std::string it_key = it->name.GetString();
-    if (it_key != "SS" && it_key != "BS" && it_key != "NS") {
-        return {"", nullptr};
-    }
-    return std::make_pair(it_key, &(it->value));
-}
-
 // Take two JSON-encoded list values (remember that a list value is
 // {"L": [...the actual list]}) and return the concatenation, again as
 // a list value.
diff --git a/alternator/serialization.cc b/alternator/serialization.cc
index 4441b6a502..2c6769288d 100644
--- a/alternator/serialization.cc
+++ b/alternator/serialization.cc
@@ -246,4 +246,16 @@ big_decimal unwrap_number(const rjson::value& v, std::string_view diagnostic) {
     return big_decimal(it->value.GetString());
 }
 
+const std::pair<std::string, const rjson::value*> unwrap_set(const rjson::value& v) {
+    if (!v.IsObject() || v.MemberCount() != 1) {
+        return {"", nullptr};
+    }
+    auto it = v.MemberBegin();
+    const std::string it_key = it->name.GetString();
+    if (it_key != "SS" && it_key != "BS" && it_key != "NS") {
+        return {"", nullptr};
+    }
+    return std::make_pair(it_key, &(it->value));
+}
+
 }
diff --git a/alternator/serialization.hh b/alternator/serialization.hh
index 50a550b2e3..95cc15732c 100644
--- a/alternator/serialization.hh
+++ b/alternator/serialization.hh
@@ -63,4 +63,10 @@ clustering_key ck_from_json(const rjson::value& item, schema_ptr schema);
 // If v encodes a number (i.e., it is a {"N": [...]}, returns an object representing it.  Otherwise,
 // raises ValidationException with diagnostic.
 big_decimal unwrap_number(const rjson::value& v, std::string_view diagnostic);
+
+// Check if a given JSON object encodes a set (i.e., it is a {"SS": [...]}, or "NS", "BS"
+// and returns set's type and a pointer to that set. If the object does not encode a set,
+// returned value is {"", nullptr}
+const std::pair<std::string, const rjson::value*> unwrap_set(const rjson::value& v);
+
 }