diff --git a/package/debian/matemat/DEBIAN/postinst b/package/debian/matemat/DEBIAN/postinst
index 305e6de..d94076b 100755
--- a/package/debian/matemat/DEBIAN/postinst
+++ b/package/debian/matemat/DEBIAN/postinst
@@ -13,7 +13,7 @@ if [[ "$1" == "configure" ]]; then
     fi
 
     chown matemat:matemat -R /var/lib/matemat
-    find /var/lib/matemat -type d -exec chmod 0750 {}
-    find /var/lib/matemat -type f -exec chmod 0640 {}
+    find /var/lib/matemat -type d -exec chmod 0750 {} \;
+    find /var/lib/matemat -type f -exec chmod 0640 {} \;
 
 fi