diff --git a/gnu/packages/ebook.scm b/gnu/packages/ebook.scm
index a8c6f5975b..659ec57d50 100644
--- a/gnu/packages/ebook.scm
+++ b/gnu/packages/ebook.scm
@@ -116,6 +116,7 @@ (define-public calibre
        ("libusb" ,libusb)
        ("libxrender" ,libxrender)
        ("openssl" ,openssl)
+       ("optipng" ,optipng)
        ("podofo" ,podofo)
        ("poppler" ,poppler)
        ("python" ,python-2)