diff --git a/README.md b/README.md
index c2447e1..e71e7ff 100644
--- a/README.md
+++ b/README.md
@@ -28,7 +28,7 @@ val mailsWithEInvoices = mailReader.listAllMessagesWithEInvoice(MailAccount(
     username = "", // your mail account username
     password = "", // your mail account username
     serverAddress = "", // IMAP server address
-    port = null // IMAP server port, leave null if default port 993
+    port = null // IMAP server port, can be left null for default port 993
 ))
 ```
 
diff --git a/e-invoice-domain/src/test/kotlin/net/codinux/invoicing/Demonstration.kt b/e-invoice-domain/src/test/kotlin/net/codinux/invoicing/Demonstration.kt
index 1e4ac16..091cc0c 100644
--- a/e-invoice-domain/src/test/kotlin/net/codinux/invoicing/Demonstration.kt
+++ b/e-invoice-domain/src/test/kotlin/net/codinux/invoicing/Demonstration.kt
@@ -31,7 +31,7 @@ class Demonstration {
             username = "", // your mail account username
             password = "", // your mail account username
             serverAddress = "", // IMAP server address
-            port = null // IMAP server port, leave null if default port 993
+            port = null // IMAP server port, can be left null for default port 993
         ))
     }
 
diff --git a/e-invoice-domain/src/test/kotlin/net/codinux/invoicing/mail/MailReaderTest.kt b/e-invoice-domain/src/test/kotlin/net/codinux/invoicing/mail/MailReaderTest.kt
index 4bfb9a7..bac0648 100644
--- a/e-invoice-domain/src/test/kotlin/net/codinux/invoicing/mail/MailReaderTest.kt
+++ b/e-invoice-domain/src/test/kotlin/net/codinux/invoicing/mail/MailReaderTest.kt
@@ -15,7 +15,7 @@ class MailReaderTest {
             username = "",
             password = "",
             serverAddress = "",
-            port = null // can be left as null if default port 993 is used
+            port = null // IMAP server port, can be left null for default port 993
         )
     }