diff --git a/include/valijson/adapters/poco_json_adapter.hpp b/include/valijson/adapters/poco_json_adapter.hpp
index a997deb..6bc5a3e 100644
--- a/include/valijson/adapters/poco_json_adapter.hpp
+++ b/include/valijson/adapters/poco_json_adapter.hpp
@@ -346,7 +346,7 @@ public:
     bool getInteger(int64_t &result) const
     {
         if (m_value.isInteger()) {
-            result = m_value.convert<int>();
+            result = m_value.convert<int64_t>();
             return true;
         }
         return false;