diff --git a/guix/build/gnu-build-system.scm b/guix/build/gnu-build-system.scm
index e2aa0e1799..f82fa68b7a 100644
--- a/guix/build/gnu-build-system.scm
+++ b/guix/build/gnu-build-system.scm
@@ -60,6 +60,7 @@ (define* (configure #:key outputs (configure-flags '()) #:allow-other-keys)
   (let ((prefix     (assoc-ref outputs "out"))
         (libdir     (assoc-ref outputs "lib"))
         (includedir (assoc-ref outputs "include")))
+    (format #t "configure flags: ~s~%" configure-flags)
     (zero? (apply system* "./configure"
                   "--enable-fast-install"
                   (string-append "--prefix=" prefix)