diff --git a/src/EthSmartContractIO/ContractIO/ContractIO.cs b/src/EthSmartContractIO/ContractIO/ContractIO.cs
index 735db34..d77bde3 100644
--- a/src/EthSmartContractIO/ContractIO/ContractIO.cs
+++ b/src/EthSmartContractIO/ContractIO/ContractIO.cs
@@ -10,11 +10,18 @@ public class ContractIO
 {
     private readonly IServiceProvider? serviceProvider;
 
+    /// <summary>
+    /// Initializes a new instance of the <see cref="ContractIO"/> class.
+    /// </summary>
+    public ContractIO()
+        : this(null)
+    { }
+
     /// <summary>
     /// Initializes a new instance of the <see cref="ContractIO"/> class.
     /// </summary>
     /// <param name="serviceProvider">The service provider to use. If null, a new one will be created. Used only for write request.</param>
-    public ContractIO(IServiceProvider? serviceProvider = null)
+    public ContractIO(IServiceProvider? serviceProvider)
     {
         this.serviceProvider = serviceProvider;
     }