diff --git a/ob-prolog.el b/ob-prolog.el
index 354578f..c2ce0af 100644
--- a/ob-prolog.el
+++ b/ob-prolog.el
@@ -58,7 +58,7 @@
 
 (defconst org-babel-header-args:prolog
   '((:goal . :any))
-  "Prolog specific header arguments.")
+  "Prolog-specific header arguments.")
 
 
 (defvar org-babel-default-header-args:prolog