diff --git a/testsuite/rsa-encrypt-test.c b/testsuite/rsa-encrypt-test.c
index c1e901be4822af87a97423bedd394bc67ae2926e..2c1373fe5c73d8dd55997ceaa34d1a465e4ad4c2 100644
--- a/testsuite/rsa-encrypt-test.c
+++ b/testsuite/rsa-encrypt-test.c
@@ -38,7 +38,11 @@ test_main(void)
 		     gibberish));
 
   if (verbose)
-    gmp_fprintf(stderr, "encrypted: %Zd\n", gibberish);
+    {
+      /* In which GMP version was gmp_fprintf introduced? */
+      fprintf(stderr, "encrypted: ");
+      mpz_out_str(stderr, 10, gibberish);
+    }
   
   decrypted = alloca(msg_length + 1);