diff --git a/README.md b/README.md
index 13c9492..0a112ec 100644
--- a/README.md
+++ b/README.md
@@ -78,7 +78,11 @@ $response = $command
     ->run()
 ;
 
-if ($response->isSuccessful()) {
+// Check if the command failed and get the error if needed
+if ($response->hasFailed()) {
+    throw new Exception('An error occurred:'.$response->getError());
+}
+else {
     // If it has not failed, then we simply send it to the buffer
     header('Content-type: image/gif');
     echo file_get_contents('logo.gif');
@@ -109,9 +113,14 @@ $response = $command
     ->run()
 ;
 
-if ($response->isSuccessful()) {
-    header('Content-type: image/jpeg');
-    echo file_get_contents('background.jpeg');
+// Check if the command failed and get the error if needed
+if ($response->hasFailed()) {
+    throw new Exception('An error occurred:'.$response->getError());
+}
+else {
+    // If it has not failed, then we simply send it to the buffer
+    header('Content-type: image/gif');
+    echo file_get_contents('logo.gif');
 }
 ```