diff --git a/docs/aptpkg.1.scd b/docs/aptpkg.1.scd
index a4375d4..35cddf8 100644
--- a/docs/aptpkg.1.scd
+++ b/docs/aptpkg.1.scd
@@ -19,7 +19,8 @@ a tool such as *reprepro*(1).
 
 Provide aptpkg with a path to a folder containing an *aptpkg*(5) build file.
 The --auto option can also be used to build modified packages based on a git
-commit hash, using _HEAD_ if one is not provided.
+commit hash, using _HEAD_ if one is not provided. The aptpkg script *must* be
+available in $PATH.
 
 # SEE ALSO