diff --git a/integrations/azure_ai_search/src/haystack_integrations/document_stores/azure_ai_search/filters.py b/integrations/azure_ai_search/src/haystack_integrations/document_stores/azure_ai_search/filters.py
index 0f105bc91..37636d1c5 100644
--- a/integrations/azure_ai_search/src/haystack_integrations/document_stores/azure_ai_search/filters.py
+++ b/integrations/azure_ai_search/src/haystack_integrations/document_stores/azure_ai_search/filters.py
@@ -79,8 +79,8 @@ def _in(field: str, value: Any) -> str:
     if not isinstance(value, list) or any(not isinstance(v, str) for v in value):
         msg = "Azure AI Search only supports a list of strings for 'in' comparators"
         raise AzureAISearchDocumentStoreFilterError(msg)
-    values = ", ".join(map(str, value))
-    return f"search.in({field},'{values}')"
+    values = ",".join(map(str, value))
+    return f"search.in({field},'{values}',',')"
 
 
 def _comparison_operator(field: str, value: Any, operator: str) -> str: