diff --git a/neptune/internal/backends/hosted_neptune_backend.py b/neptune/internal/backends/hosted_neptune_backend.py
index 8befade58..f2fdd5221 100644
--- a/neptune/internal/backends/hosted_neptune_backend.py
+++ b/neptune/internal/backends/hosted_neptune_backend.py
@@ -796,7 +796,7 @@ def _convert_to_api_properties(self, raw_properties):
         return [
             KeyValueProperty(
                 key=key,
-                value=value
+                value=str(value)
             ) for key, value in raw_properties.items()
         ]