diff --git a/csharp/src/Drivers/BigQuery/BigQueryConnection.cs b/csharp/src/Drivers/BigQuery/BigQueryConnection.cs
index 711ee02cb4..35f2adf464 100644
--- a/csharp/src/Drivers/BigQuery/BigQueryConnection.cs
+++ b/csharp/src/Drivers/BigQuery/BigQueryConnection.cs
@@ -85,9 +85,10 @@ internal void Open()
             if (!this.properties.TryGetValue(BigQueryParameters.ProjectId, out projectId))
                 throw new ArgumentException($"The {BigQueryParameters.ProjectId} parameter is not present");
 
-            if (this.properties.ContainsKey(BigQueryParameters.AuthenticationType))
+            if (this.properties.TryGetValue(BigQueryParameters.AuthenticationType, out string? newAuthenticationType))
             {
-                authenticationType = this.properties[BigQueryParameters.AuthenticationType];
+                if (!string.IsNullOrEmpty(newAuthenticationType))
+                    authenticationType = newAuthenticationType;
 
                 if (!authenticationType.Equals(BigQueryConstants.UserAuthenticationType, StringComparison.OrdinalIgnoreCase) &&
                     !authenticationType.Equals(BigQueryConstants.ServiceAccountAuthenticationType, StringComparison.OrdinalIgnoreCase))