diff --git a/include/bej_decoder_core.h b/include/bej_decoder_core.h
index 2c7f066..a0c4686 100644
--- a/include/bej_decoder_core.h
+++ b/include/bej_decoder_core.h
@@ -103,7 +103,7 @@
         /**
          * @brief Calls when an Integer property is found.
          */
-        int (*callbackInteger)(const char* propertyName, uint64_t value,
+        int (*callbackInteger)(const char* propertyName, int64_t value,
                                void* dataPtr);
 
         /**
diff --git a/include/rde_common.h b/include/rde_common.h
index f377507..bc5498c 100644
--- a/include/rde_common.h
+++ b/include/rde_common.h
@@ -34,6 +34,7 @@
         bejErrorUnknownProperty,
         bejErrorInvalidSchemaType,
         bejErrorInvalidPropertyOffset,
+        bejErrorNullParameter,
     };
 
     /**