diff --git a/OpenAI.SDK/EndpointProviders/AzureOpenAiEndpointProvider.cs b/OpenAI.SDK/EndpointProviders/AzureOpenAiEndpointProvider.cs
index 100e665b..c7bbaccd 100644
--- a/OpenAI.SDK/EndpointProviders/AzureOpenAiEndpointProvider.cs
+++ b/OpenAI.SDK/EndpointProviders/AzureOpenAiEndpointProvider.cs
@@ -211,7 +211,7 @@ public string AssistantList(PaginationRequest? assistantListRequest)
         var query = assistantListRequest?.GetQueryParameters();
         if (!string.IsNullOrWhiteSpace(query))
         {
-            url = $"{url}{query}";
+            url = $"{url}&{query}";
         }
 
         return url;
@@ -239,7 +239,7 @@ public string AssistantFileList(string assistantId, PaginationRequest? assistant
         var query = assistantFileListRequest?.GetQueryParameters();
         if (!string.IsNullOrWhiteSpace(query))
         {
-            url = $"{url}{query}";
+            url = $"{url}&{query}";
         }
 
         return url;
@@ -287,7 +287,7 @@ public string MessageList(string threadId, PaginationRequest? messageListRequest
         var query = messageListRequest?.GetQueryParameters();
         if (!string.IsNullOrWhiteSpace(query))
         {
-            url = $"{url}{query}";
+            url = $"{url}&{query}";
         }
 
         return url;
@@ -320,7 +320,7 @@ public string RunList(string threadId, PaginationRequest? runListRequest)
         var query = runListRequest?.GetQueryParameters();
         if (!string.IsNullOrWhiteSpace(query))
         {
-            url = $"{url}{query}";
+            url = $"{url}&{query}";
         }
 
         return url;
@@ -353,7 +353,7 @@ public string RunStepList(string threadId, string runId, PaginationRequest? runS
         var query = runStepListRequest?.GetQueryParameters();
         if (!string.IsNullOrWhiteSpace(query))
         {
-            url = $"{url}{query}";
+            url = $"{url}&{query}";
         }
 
         return url;
@@ -372,7 +372,7 @@ public string VectorStoreList(PaginationRequest baseListRequest)
         var query = baseListRequest?.GetQueryParameters();
         if (!string.IsNullOrWhiteSpace(query))
         {
-            url = $"{url}?{query}";
+            url = $"{url}&{query}";
         }
 
         return url;
@@ -415,7 +415,7 @@ public string VectorStoreFileList(string vectorStoreId, VectorStoreFileListReque
         var query = baseListRequest?.GetQueryParameters();
         if (!string.IsNullOrWhiteSpace(query))
         {
-            url = $"{url}?{query}";
+            url = $"{url}&{query}";
         }
 
         return url;
@@ -443,7 +443,7 @@ public string VectorStoreFileBatchList(string vectorStoreId, string batchId, Pag
         var query = baseListRequest?.GetQueryParameters();
         if (!string.IsNullOrWhiteSpace(query))
         {
-            url = $"{url}?{query}";
+            url = $"{url}&{query}";
         }
 
         return url;