diff --git a/lib/api.js b/lib/api.js
index 461dcfea..f7eb2df5 100644
--- a/lib/api.js
+++ b/lib/api.js
@@ -145,8 +145,15 @@ class API {
 
     this.collector = new DataCollector(this.instrumenter.instrumentationData);
 
-    this.providerOptions.gasLimit = this.gasLimitString;
-    this.providerOptions.allowUnlimitedContractSize = true;
+    this.providerOptions.gasLimit =
+      'gasLimit' in this.providerOptions
+        ? this.providerOptions.gasLimit
+        : this.gasLimitString;
+
+    this.providerOptions.allowUnlimitedContractSize =
+      'allowUnlimitedContractSize' in this.providerOptions
+        ? this.providerOptions.allowUnlimitedContractSize
+        : true;
 
     // Attach to vm step of supplied client
     try {