diff --git a/CHANGELOG.md b/CHANGELOG.md
index a45b512..723180d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,12 @@
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.1.3] - 2024/11/..
+
+### `Fixed`
+
+- Converted `data[sample_id]` to a string in the `format_df` function with `assign.py` to prevent `AttributeErrors` when non-string values are in the genomic address.
+
 ## v1.0dev - [date]
 
 Initial release of phac-nml/genomic_address_service
@@ -16,3 +22,5 @@ Changed README format to standard DAAD README, added useage arguments.
 ### `Dependencies`
 
 ### `Deprecated`
+
+[0.1.3]: https://github.com/phac-nml/genomic_address_service/releases/tag/0.1.3
diff --git a/genomic_address_service/classes/assign.py b/genomic_address_service/classes/assign.py
index c1782d4..30977ff 100644
--- a/genomic_address_service/classes/assign.py
+++ b/genomic_address_service/classes/assign.py
@@ -85,7 +85,7 @@ def format_df(self,data,delim='.'):
         self.error_samples = []
         membership = {}
         for sample_id in data:
-            address = data[sample_id].split(delim)
+            address = str(data[sample_id]).split(delim)
             if len(address) != num_thresholds:
                 self.error_samples.append(sample_id)
                 continue