diff --git a/src/EntityManager.cpp b/src/EntityManager.cpp
index 9198ee5..d993860 100644
--- a/src/EntityManager.cpp
+++ b/src/EntityManager.cpp
@@ -1115,15 +1115,25 @@
             }
         }
     }
+
+    // convert hex numbers to ints
     else if (boost::starts_with(value, "0x"))
     {
         try
         {
-            keyPair.value() = static_cast<uint64_t>(std::stoul(value, 0, 0));
+            size_t pos = 0;
+            int64_t temp = std::stoul(value, &pos, 0);
+            if (pos == value.size())
+            {
+                keyPair.value() = static_cast<uint64_t>(temp);
+            }
         }
         catch (std::invalid_argument)
         {
         }
+        catch (std::out_of_range)
+        {
+        }
     }
 }