diff --git a/gnu/packages/libusb.scm b/gnu/packages/libusb.scm
index dd8a2ff23be64c1bfc152e92f2bbc105b15d3f2a..17f71eba8df8c6ca92f43222b1ec2a51bd866ce0 100644
--- a/gnu/packages/libusb.scm
+++ b/gnu/packages/libusb.scm
@@ -67,7 +67,8 @@ (define-public libmtp
     (build-system gnu-build-system)
     (native-inputs
      `(("pkg-config" ,pkg-config)))
-    (inputs
+    (propagated-inputs
+     ;; libmtp.pc refers to all these.
      `(("libgcrypt" ,libgcrypt)
        ("libusb" ,libusb)))
     (arguments