diff --git a/ChangeLog b/ChangeLog
index 820f1bd5f0ee40074b1d65de00ae9d2f5ee342ac..723524df007c9b656fc9ab1170813cbd78560697 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2014-06-25  Niels Möller  <nisse@lysator.liu.se>
 
+	* testsuite/ecdsa-keygen-test.c (test_main): Use printf,
+	mpz_out_str and write_mpn instead of gmp_fprintf.
+	* testsuite/ecdsa-sign-test.c (test_ecdsa): Likewise.
+	* testsuite/ecdsa-verify-test.c (test_ecdsa): Likewise.
+
 	* dsa.h: Include bignum.h instead of gmp.h.
 	* ecc-internal.h: Likewise.
 	* ecc.h: Likewise.
diff --git a/testsuite/ecdsa-keygen-test.c b/testsuite/ecdsa-keygen-test.c
index 7c25421a9e8b059068666327cb594e3f3ef998af..e1ae26e0fc22bb916bf62b7b994e028c65dd88f9 100644
--- a/testsuite/ecdsa-keygen-test.c
+++ b/testsuite/ecdsa-keygen-test.c
@@ -71,11 +71,13 @@ test_main (void)
 
       if (verbose)
 	{
-	  gmp_fprintf (stderr,
-		       "Public key:\nx = %Nx\ny = %Nx\n",
-		       pub.p, ecc->size, pub.p + ecc->size, ecc->size);
-	  gmp_fprintf (stderr,
-		       "Private key: %Nx\n", key.p, ecc->size);
+	  fprintf (stderr, "Public key:\nx = ");
+	  write_mpn (stderr, 16, pub.p, ecc->size);
+	  fprintf (stderr, "\ny = ");
+	  write_mpn (stderr, 16, pub.p + ecc->size, ecc->size);
+	  fprintf (stderr, "\nPrivate key: ");
+	  write_mpn (stderr, 16, key.p, ecc->size);
+	  fprintf (stderr, "\n");
 	}
       if (!ecc_valid_p (&pub))
 	die ("ecdsa_generate_keypair produced an invalid point.\n");
diff --git a/testsuite/ecdsa-sign-test.c b/testsuite/ecdsa-sign-test.c
index fc9ea2a58c744a88fc2be62ad1a34d2df8996cf8..9d9a173094f1520900695070360ae85bcb119c18 100644
--- a/testsuite/ecdsa-sign-test.c
+++ b/testsuite/ecdsa-sign-test.c
@@ -34,10 +34,15 @@ test_ecdsa (const struct ecc_curve *ecc,
       || mpz_limbs_cmp (ref.s, sp, ecc->size) != 0)
     {
       fprintf (stderr, "_ecdsa_sign failed, bit_size = %u\n", ecc->bit_size);
-      gmp_fprintf (stderr, "r     = %Nx\n", rp, ecc->size);
-      gmp_fprintf (stderr, "s     = %Nx\n", sp, ecc->size);
-      gmp_fprintf (stderr, "ref.r = %Zx\n", ref.r);
-      gmp_fprintf (stderr, "ref.s = %Zx\n", ref.s);
+      fprintf (stderr, "r     = ");
+      write_mpn (stderr, 16, rp, ecc->size);
+      fprintf (stderr, "\ns     = ");
+      write_mpn (stderr, 16, sp, ecc->size);
+      fprintf (stderr, "\nref.r = ");
+      mpz_out_str (stderr, 16, ref.r);
+      fprintf (stderr, "\nref.s = ");
+      mpz_out_str (stderr, 16, ref.s);
+      fprintf (stderr, "\n");
       abort();
     }
 
diff --git a/testsuite/ecdsa-verify-test.c b/testsuite/ecdsa-verify-test.c
index 5f880729b69d5813479e946829146fe0f16d4a93..d69f7637d6ad7e797ec22c1627c01c6957ad358a 100644
--- a/testsuite/ecdsa-verify-test.c
+++ b/testsuite/ecdsa-verify-test.c
@@ -29,12 +29,17 @@ test_ecdsa (const struct ecc_curve *ecc,
     {
       fprintf (stderr, "ecdsa_verify failed with valid signature.\n");
     fail:
-      fprintf (stderr, "bit_size = %u\n", ecc->bit_size);
-      gmp_fprintf (stderr, "x = %Zx\n", x);
-      gmp_fprintf (stderr, "y = %Zx\ndigest ", y);
+      fprintf (stderr, "bit_size = %u\nx = ", ecc->bit_size);
+      mpz_out_str (stderr, 16, x);
+      fprintf (stderr, "\ny = ");
+      mpz_out_str (stderr, 16, y);
+      fprintf (stderr, "\ndigest ");
       print_hex (h->length, h->data);
-      gmp_fprintf (stderr, "r = %Zx\n", signature.r);
-      gmp_fprintf (stderr, "s = %Zx\n", signature.s);
+      fprintf (stderr, "r = ");
+      mpz_out_str (stderr, 16, signature.r);
+      fprintf (stderr, "\ns = ");
+      mpz_out_str (stderr, 16, signature.s);
+      fprintf (stderr, "\n");
       abort();
     }