diff --git a/core/engine.go b/core/engine.go
index ae98a07..057809d 100644
--- a/core/engine.go
+++ b/core/engine.go
@@ -139,6 +139,15 @@ func (e *Engine) BuildHTTPClient(replaceDefault ...bool) *Engine {
 	return e
 }
 
+// SetHTTPClient sets HTTP client to engine
+func (e *Engine) SetHTTPClient(client *http.Client) *Engine {
+	if client != nil {
+		e.httpClient = client
+	}
+
+	return e
+}
+
 // HTTPClient returns inner http client or default http client
 func (e *Engine) HTTPClient() *http.Client {
 	if e.httpClient == nil {
diff --git a/core/http_client_builder.go b/core/http_client_builder.go
index 41a0be3..2b53b4c 100644
--- a/core/http_client_builder.go
+++ b/core/http_client_builder.go
@@ -117,8 +117,8 @@ func (b *HTTPClientBuilder) FromConfig(config *HTTPClientConfig) *HTTPClientBuil
 	}
 
 	if config.MockAddress != "" {
-		b.mockAddress = config.MockAddress
-		b.mockedDomains = config.MockedDomains
+		b.SetMockAddress(config.MockAddress)
+		b.SetMockedDomains(config.MockedDomains)
 	}
 
 	if config.Timeout > 0 {