diff --git a/src/util/rsa.c b/src/util/rsa.c
index 0b533615c..d85f3cc86 100644
--- a/src/util/rsa.c
+++ b/src/util/rsa.c
@@ -670,8 +670,8 @@ decode_public_key (const struct TALER_RSA_PublicKeyBinaryEncoded *publicKey)
 
 
 /**
- * Verify signature on the given message.  The size of the message should be less than
- * TALER_RSA_DATA_ENCODING_LENGTH (256) bytes.
+ * Verify signature on the given message.  The size of the message should be
+ * less than TALER_RSA_DATA_ENCODING_LENGTH (256) bytes.
  *
  * @param msg the message
  * @param size the size of the message
@@ -690,7 +690,7 @@ TALER_RSA_verify (const void *msg, size_t size,
   gcry_mpi_t val;
   gcry_sexp_t psexp;
   size_t erroff;
-  int rc;
+  gcry_error_t rc;
 
   GNUNET_assert (size <= TALER_RSA_DATA_ENCODING_LENGTH);
   if (size > TALER_RSA_DATA_ENCODING_LENGTH)
diff --git a/src/util/test_rsa.c b/src/util/test_rsa.c
index 1f7adfd6c..fdacf5212 100644
--- a/src/util/test_rsa.c
+++ b/src/util/test_rsa.c
@@ -38,7 +38,7 @@
 int
 main (int argc, char *argv[])
 {
-#define RND_BLK_SIZE 4096
+#define RND_BLK_SIZE 16524
   unsigned char rnd_blk[RND_BLK_SIZE];
   struct TALER_RSA_PrivateKey *priv;
   struct TALER_RSA_PrivateKeyBinaryEncoded *priv_enc;
@@ -72,6 +72,12 @@ main (int argc, char *argv[])
   EXITIF (GNUNET_OK != TALER_RSA_verify (&hash, sizeof (hash),
                                          &sig,
                                          &pubkey));
+  /* corrupt our hash and see if the signature is still valid */
+  GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_WEAK, &hash,
+                              sizeof (struct GNUNET_HashCode));
+  EXITIF (GNUNET_OK == TALER_RSA_verify (&hash, sizeof (hash),
+                                         &sig,
+                                         &pubkey));
 
   /* test blind signing */
   GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_WEAK, rnd_blk,
@@ -92,6 +98,12 @@ main (int argc, char *argv[])
   EXITIF (GNUNET_OK != TALER_RSA_verify (&hash, sizeof (hash),
                                          &sig,
                                          &pubkey));
+  /* corrupt our hash and see if the signature is still valid */
+  GNUNET_CRYPTO_random_block (GNUNET_CRYPTO_QUALITY_WEAK, &hash,
+                              sizeof (struct GNUNET_HashCode));
+  EXITIF (GNUNET_OK == TALER_RSA_verify (&hash, sizeof (hash),
+                                         &sig,
+                                         &pubkey));
   ret = 0;                      /* all OK */
 
  EXITIF_exit: