diff --git a/ChangeLog b/ChangeLog
index 725d22de743640a88ccaf574481f61911c1ec033..e8034e1615337e364abda4826ee206a031d4ba62 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2016-08-16  Niels Möller  <nisse@lysator.liu.se>
 
+	* sexp.c (sexp_iterator_check_type, sexp_iterator_check_types)
+	(sexp_iterator_assoc): Use const char * for caller's expression
+	types. Updated all callers.
+
 	* rsa2openpgp.c (rsa_keypair_to_openpgp): Added cast to const
 	uint8_t *.
 
diff --git a/sexp.c b/sexp.c
index 4073d683970327711b1ea60467ca6ee490c730cf..eb8da63306b59873302e2564558e73aad26f1d4f 100644
--- a/sexp.c
+++ b/sexp.c
@@ -295,7 +295,7 @@ sexp_iterator_get_uint32(struct sexp_iterator *iterator,
 
 int
 sexp_iterator_check_type(struct sexp_iterator *iterator,
-			 const uint8_t *type)
+			 const char *type)
 {
   return (sexp_iterator_enter_list(iterator)
 	  && iterator->type == SEXP_ATOM
@@ -305,10 +305,10 @@ sexp_iterator_check_type(struct sexp_iterator *iterator,
 	  && sexp_iterator_next(iterator));
 }
 
-const uint8_t *
+const char *
 sexp_iterator_check_types(struct sexp_iterator *iterator,
 			  unsigned ntypes,
-			  const uint8_t * const *types)
+			  const char * const *types)
 {
   if (sexp_iterator_enter_list(iterator)
       && iterator->type == SEXP_ATOM
@@ -327,7 +327,7 @@ sexp_iterator_check_types(struct sexp_iterator *iterator,
 int
 sexp_iterator_assoc(struct sexp_iterator *iterator,
 		    unsigned nkeys,
-		    const uint8_t * const *keys,
+		    const char * const *keys,
 		    struct sexp_iterator *values)
 {
   TMP_DECL(found, int, NETTLE_MAX_SEXP_ASSOC);
diff --git a/sexp.h b/sexp.h
index a01e6a508a8b22e82371e95e71920dc7b01ad75b..039a537b4e9eb2ffcace7dc628d466a5927e01cf 100644
--- a/sexp.h
+++ b/sexp.h
@@ -130,12 +130,12 @@ sexp_iterator_get_uint32(struct sexp_iterator *iterator,
  */
 int
 sexp_iterator_check_type(struct sexp_iterator *iterator,
-			 const uint8_t *type);
+			 const char *type);
 
-const uint8_t *
+const char *
 sexp_iterator_check_types(struct sexp_iterator *iterator,
 			  unsigned ntypes,
-			  const uint8_t * const *types);
+			  const char * const *types);
 
 /* Current element must be a list. Looks up element of type
  *
@@ -149,7 +149,7 @@ sexp_iterator_check_types(struct sexp_iterator *iterator,
 int
 sexp_iterator_assoc(struct sexp_iterator *iterator,
 		    unsigned nkeys,
-		    const uint8_t * const *keys,
+		    const char * const *keys,
 		    struct sexp_iterator *values);
 
 
diff --git a/sexp2dsa.c b/sexp2dsa.c
index 74b3470567905fc6b6695f416427cb4b81ce7b9e..948859935156d9eb7f82ae1ab873b66411cfb9a5 100644
--- a/sexp2dsa.c
+++ b/sexp2dsa.c
@@ -61,7 +61,7 @@ dsa_keypair_from_sexp_alist(struct dsa_params *params,
 			    unsigned q_bits,
 			    struct sexp_iterator *i)
 {
-  static const uint8_t * const names[5]
+  static const char * const names[5]
     = { "p", "q", "g", "y", "x" };
   struct sexp_iterator values[5];
   unsigned nvalues = priv ? 5 : 4;
@@ -131,7 +131,7 @@ dsa_signature_from_sexp(struct dsa_signature *rs,
 			struct sexp_iterator *i,
 			unsigned q_bits)
 {
-  static const uint8_t * const names[2] = { "r", "s" };
+  static const char * const names[2] = { "r", "s" };
   struct sexp_iterator values[2];
 
   if (!sexp_iterator_assoc(i, 2, names, values))
diff --git a/sexp2rsa.c b/sexp2rsa.c
index 7a664fd59c4ea90a75b2b707b6ba1f336c7d7130..527104367f88ec9c5884c6279ec824813ac35742 100644
--- a/sexp2rsa.c
+++ b/sexp2rsa.c
@@ -59,7 +59,7 @@ rsa_keypair_from_sexp_alist(struct rsa_public_key *pub,
 			    unsigned limit,
 			    struct sexp_iterator *i)
 {
-  static const uint8_t * const names[8]
+  static const char * const names[8]
     = { "n", "e", "d", "p", "q", "a", "b", "c" };
   struct sexp_iterator values[8];
   unsigned nvalues = priv ? 8 : 2;
@@ -99,7 +99,7 @@ rsa_keypair_from_sexp(struct rsa_public_key *pub,
 		      size_t length, const uint8_t *expr)
 {
   struct sexp_iterator i;
-  static const uint8_t * const names[3]
+  static const char * const names[3]
     = { "rsa", "rsa-pkcs1", "rsa-pkcs1-sha1" };
 
   if (!sexp_iterator_first(&i, length, expr))