diff --git a/README.md b/README.md
index 56c0753..d790c35 100644
--- a/README.md
+++ b/README.md
@@ -13,6 +13,7 @@ A lightweight, pure Perl markdown to HTML converter that uses a state machine fo
 ## Requirements
 
 - Perl 5.42 or higher
+- Getopt::Long (but it's already installed on most Perl installations)
 
 ## Installation