diff --git a/pkgs/htdp-pkgs/htdp-lib/htdp/matrix.rkt b/pkgs/htdp-pkgs/htdp-lib/htdp/matrix.rkt
index f9dd89454d..85e925a63e 100644
--- a/pkgs/htdp-pkgs/htdp-lib/htdp/matrix.rkt
+++ b/pkgs/htdp-pkgs/htdp-lib/htdp/matrix.rkt
@@ -192,3 +192,4 @@ position structures returned by matrix-where?
 (define-values/invoke-unit invisible-matrix@ (import) (export matrix^))
 
 (provide-signature-elements matrix^)
+(provide snip-class)