diff --git a/plugins/plus b/plugins/plus
new file mode 100644
index 0000000..b85b3e8
--- /dev/null
+++ b/plugins/plus
@@ -0,0 +1,45 @@
+#!perl
+
+HELP "+<N>" => "Add N more items of the previous thing";
+
+my $limit = 200;
+my $err_limit = "Repetition is limited at $limit items.";
+my $err_pfand = "Plugins 'pfand' and 'repeat' cannot be combined.";
+
+sub command {
+    my ($self, $cart, $command) = @_;
+
+    return ABORT, $err_pfand if $cart->entries('is_pfand');
+
+    my ($post) = $command =~ /^\+(\d+)?$/
+        or return NEXT;
+
+    return ABORT, "Can't modify an empty transaction." if not $cart->size;
+
+    my $last = ($cart->entries)[-1];
+
+    return REJECT, "Addition only works on products." if not $last->has_attribute('product_id');
+
+    if ($post) {
+        return REJECT, $err_limit if $last->quantity + $post > $limit;
+
+        $last->quantity($last->quantity + $post);
+        return ACCEPT;
+    }
+
+    return "Add to previous product", \&add;
+}
+
+sub add {
+    my ($self, $cart, $arg) = @_;
+
+    $arg =~ /^\d+$/ and $arg > 0
+        or return REJECT, "Invalid value.";
+
+    my $last = ($cart->entries)[-1];
+    return REJECT, $err_limit if $last->quantity + $arg > $limit;
+
+    $last->quantity($last->quantity + $arg);
+    return ACCEPT;
+}
+