diff --git a/include/chibi/sexp.h b/include/chibi/sexp.h
index 6737e2a8..fb8e33b1 100644
--- a/include/chibi/sexp.h
+++ b/include/chibi/sexp.h
@@ -134,7 +134,6 @@ typedef struct sexp_struct *sexp;
 #endif
 
 /* procedure types */
-typedef sexp (*sexp_proc0) (void);
 typedef sexp (*sexp_proc1) (sexp sexp_api_params(self, n));
 typedef sexp (*sexp_proc2) (sexp sexp_api_params(self, n), sexp);
 typedef sexp (*sexp_proc3) (sexp sexp_api_params(self, n), sexp, sexp);
@@ -921,6 +920,7 @@ SEXP_API sexp sexp_finalize_c_type (sexp ctx sexp_api_params(self, n), sexp obj)
 #define sexp_get_output_string(ctx, out) sexp_get_output_string_op(ctx sexp_api_pass(NULL, 1), out)
 #define sexp_expt(ctx, a, b) sexp_expt_op(ctx sexp_api_pass(NULL, 2), a, b)
 #define sexp_register_simple_type(ctx, a, b) sexp_register_simple_type_op(ctx sexp_api_pass(NULL, 2), a, b)
+#define sexp_register_type(ctx, a, b, c, d, e, f, g, h, i, j) sexp_register_type_op(ctx sexp_api_pass(NULL, 10), a, b, c, d, e, f, g, h, i, j)
 #define sexp_make_type_predicate(ctx, a, b) sexp_make_type_predicate_op(ctx sexp_api_pass(NULL, 2), a, b)
 #define sexp_make_constructor(ctx, a, b) sexp_make_constructor_op(ctx sexp_api_pass(NULL, 2), a, b)
 #define sexp_make_getter(ctx, a, b, c) sexp_make_getter_op(ctx sexp_api_pass(NULL, 3), a, b, c)
diff --git a/lib/srfi/27/rand.c b/lib/srfi/27/rand.c
index 25aff799..210b9e42 100644
--- a/lib/srfi/27/rand.c
+++ b/lib/srfi/27/rand.c
@@ -37,17 +37,17 @@ typedef struct random_data sexp_random_t;
 static sexp_uint_t rs_type_id;
 static sexp default_random_source;
 
-static sexp sexp_rs_random_integer (sexp ctx, sexp rs, sexp bound) {
+static sexp sexp_rs_random_integer (sexp ctx sexp_api_params(self, n), sexp rs, sexp bound) {
   sexp res;
-  int32_t n;
+  int32_t m;
 #if SEXP_USE_BIGNUMS
   int32_t hi, mod, len, i, *data;
 #endif
   if (! sexp_random_source_p(rs))
     res = sexp_type_exception(ctx, "not a random-source", rs);
   if (sexp_fixnump(bound)) {
-    sexp_call_random(rs, n);
-    res = sexp_make_fixnum(n % sexp_unbox_fixnum(bound));
+    sexp_call_random(rs, m);
+    res = sexp_make_fixnum(m % sexp_unbox_fixnum(bound));
 #if SEXP_USE_BIGNUMS
   } else if (sexp_bignump(bound)) {
     hi = sexp_bignum_hi(bound);
@@ -55,13 +55,13 @@ static sexp sexp_rs_random_integer (sexp ctx, sexp rs, sexp bound) {
     res = sexp_make_bignum(ctx, hi);
     data = (int32_t*) sexp_bignum_data(res);
     for (i=0; i<len-1; i++) {
-      sexp_call_random(rs, n);
-      data[i] = n;
+      sexp_call_random(rs, m);
+      data[i] = m;
     }
-    sexp_call_random(rs, n);
+    sexp_call_random(rs, m);
     mod = sexp_bignum_data(bound)[hi-1] * sizeof(int32_t) / sizeof(sexp_uint_t);
     if (mod)
-      data[i] = n % mod;
+      data[i] = m % mod;
 #endif
   } else {
     res = sexp_type_exception(ctx, "random-integer: not an integer", bound);
@@ -69,11 +69,11 @@ static sexp sexp_rs_random_integer (sexp ctx, sexp rs, sexp bound) {
   return res;
 }
 
-static sexp sexp_random_integer (sexp ctx, sexp bound) {
-  return sexp_rs_random_integer(ctx, default_random_source, bound);
+static sexp sexp_random_integer (sexp ctx sexp_api_params(self, n), sexp bound) {
+  return sexp_rs_random_integer(ctx sexp_api_pass(self, n), default_random_source, bound);
 }
 
-static sexp sexp_rs_random_real (sexp ctx, sexp rs) {
+static sexp sexp_rs_random_real (sexp ctx sexp_api_params(self, n), sexp rs) {
   int32_t res;
   if (! sexp_random_source_p(rs))
     return sexp_type_exception(ctx, "not a random-source", rs);
@@ -81,27 +81,27 @@ static sexp sexp_rs_random_real (sexp ctx, sexp rs) {
   return sexp_make_flonum(ctx, (double)res / (double)RAND_MAX);
 }
 
-static sexp sexp_random_real (sexp ctx) {
-  return sexp_rs_random_real(ctx, default_random_source);
+static sexp sexp_random_real (sexp ctx sexp_api_params(self, n)) {
+  return sexp_rs_random_real(ctx sexp_api_pass(self, n), default_random_source);
 }
 
 #if SEXP_BSD
 
-static sexp sexp_make_random_source (sexp ctx) {
+static sexp sexp_make_random_source (sexp ctx sexp_api_params(self, n)) {
   sexp res;
   res = sexp_alloc_tagged(ctx, sexp_sizeof_random, rs_type_id);
   *sexp_random_data(res) = 1;
   return res;
 }
 
-static sexp sexp_random_source_state_ref (sexp ctx, sexp rs) {
+static sexp sexp_random_source_state_ref (sexp ctx sexp_api_params(self, n), sexp rs) {
   if (! sexp_random_source_p(rs))
     return sexp_type_exception(ctx, "not a random-source", rs);
   else
     return sexp_make_integer(ctx, *sexp_random_data(rs));
 }
 
-static sexp sexp_random_source_state_set (sexp ctx, sexp rs, sexp state) {
+static sexp sexp_random_source_state_set (sexp ctx sexp_api_params(self, n), sexp rs, sexp state) {
   if (! sexp_random_source_p(rs))
     return sexp_type_exception(ctx, "not a random-source", rs);
   else if (sexp_fixnump(state))
@@ -118,7 +118,7 @@ static sexp sexp_random_source_state_set (sexp ctx, sexp rs, sexp state) {
 
 #else
 
-static sexp sexp_make_random_source (sexp ctx) {
+static sexp sexp_make_random_source (sexp ctx sexp_api_params(self, n)) {
   sexp res;
   sexp_gc_var1(state);
   sexp_gc_preserve1(ctx, state);
@@ -130,14 +130,14 @@ static sexp sexp_make_random_source (sexp ctx) {
   return res;
 }
 
-static sexp sexp_random_source_state_ref (sexp ctx, sexp rs) {
+static sexp sexp_random_source_state_ref (sexp ctx sexp_api_params(self, n), sexp rs) {
   if (! sexp_random_source_p(rs))
     return sexp_type_exception(ctx, "not a random-source", rs);
   else
     return sexp_substring(ctx, sexp_random_state(rs), ZERO, STATE_SIZE);
 }
 
-static sexp sexp_random_source_state_set (sexp ctx, sexp rs, sexp state) {
+static sexp sexp_random_source_state_set (sexp ctx sexp_api_params(self, n), sexp rs, sexp state) {
   if (! sexp_random_source_p(rs))
     return sexp_type_exception(ctx, "not a random-source", rs);
   else if (! (sexp_stringp(state)
@@ -150,14 +150,14 @@ static sexp sexp_random_source_state_set (sexp ctx, sexp rs, sexp state) {
 
 #endif
 
-static sexp sexp_random_source_randomize (sexp ctx, sexp rs) {
+static sexp sexp_random_source_randomize (sexp ctx sexp_api_params(self, n), sexp rs) {
   if (! sexp_random_source_p(rs))
     return sexp_type_exception(ctx, "not a random-source", rs);
   sexp_seed_random(time(NULL), rs);
   return SEXP_VOID;
 }
 
-static sexp sexp_random_source_pseudo_randomize (sexp ctx, sexp rs, sexp seed) {
+static sexp sexp_random_source_pseudo_randomize (sexp ctx sexp_api_params(self, n), sexp rs, sexp seed) {
   if (! sexp_random_source_p(rs))
     return sexp_type_exception(ctx, "not a random-source", rs);
   if (! sexp_fixnump(seed))
@@ -193,10 +193,10 @@ sexp sexp_init_library (sexp ctx sexp_api_params(self, n), sexp env) {
   sexp_define_foreign(ctx, env, "random-source-randomize!", 1, sexp_random_source_randomize);
   sexp_define_foreign(ctx, env, "random-source-pseudo-randomize!", 2, sexp_random_source_pseudo_randomize);
 
-  default_random_source = op = sexp_make_random_source(ctx);
+  default_random_source = op = sexp_make_random_source(ctx sexp_api_pass(NULL, 0));
   name = sexp_intern(ctx, "default-random-source", -1);
   sexp_env_define(ctx, env, name, default_random_source);
-  sexp_random_source_randomize(ctx, default_random_source);
+  sexp_random_source_randomize(ctx sexp_api_pass(NULL, 0), default_random_source);
 
   sexp_gc_release2(ctx);
   return SEXP_VOID;
diff --git a/lib/srfi/33/bit.c b/lib/srfi/33/bit.c
index 4fa7f234..b2e685a5 100644
--- a/lib/srfi/33/bit.c
+++ b/lib/srfi/33/bit.c
@@ -11,7 +11,7 @@
 #define sexp_bignum_normalize(x) x
 #endif
 
-static sexp sexp_bit_and (sexp ctx, sexp x, sexp y) {
+static sexp sexp_bit_and (sexp ctx sexp_api_params(self, n), sexp x, sexp y) {
   sexp res;
 #if SEXP_USE_BIGNUMS
   sexp_sint_t len, i;
@@ -21,7 +21,7 @@ static sexp sexp_bit_and (sexp ctx, sexp x, sexp y) {
       res = (sexp) ((sexp_uint_t)x & (sexp_uint_t)y);
 #if SEXP_USE_BIGNUMS
     else if (sexp_bignump(y))
-      res = sexp_bit_and(ctx, y, x);
+      res = sexp_bit_and(ctx sexp_api_pass(self, n), y, x);
 #endif
     else
       res = sexp_type_exception(ctx, "bitwise-and: not an integer", y);
@@ -47,7 +47,7 @@ static sexp sexp_bit_and (sexp ctx, sexp x, sexp y) {
   return sexp_bignum_normalize(res);
 }
 
-static sexp sexp_bit_ior (sexp ctx, sexp x, sexp y) {
+static sexp sexp_bit_ior (sexp ctx sexp_api_params(self, n), sexp x, sexp y) {
   sexp res;
 #if SEXP_USE_BIGNUMS
   sexp_sint_t len, i;
@@ -57,7 +57,7 @@ static sexp sexp_bit_ior (sexp ctx, sexp x, sexp y) {
       res = (sexp) ((sexp_uint_t)x | (sexp_uint_t)y);
 #if SEXP_USE_BIGNUMS
     else if (sexp_bignump(y))
-      res = sexp_bit_ior(ctx, y, x);
+      res = sexp_bit_ior(ctx sexp_api_pass(self, n), y, x);
 #endif
     else
       res = sexp_type_exception(ctx, "bitwise-ior: not an integer", y);
@@ -87,7 +87,7 @@ static sexp sexp_bit_ior (sexp ctx, sexp x, sexp y) {
   return sexp_bignum_normalize(res);
 }
 
-static sexp sexp_bit_xor (sexp ctx, sexp x, sexp y) {
+static sexp sexp_bit_xor (sexp ctx sexp_api_params(self, n), sexp x, sexp y) {
   sexp res;
 #if SEXP_USE_BIGNUMS
   sexp_sint_t len, i;
@@ -97,7 +97,7 @@ static sexp sexp_bit_xor (sexp ctx, sexp x, sexp y) {
       res = sexp_make_fixnum(sexp_unbox_fixnum(x) ^ sexp_unbox_fixnum(y));
 #if SEXP_USE_BIGNUMS
     else if (sexp_bignump(y))
-      res = sexp_bit_xor(ctx, y, x);
+      res = sexp_bit_xor(ctx sexp_api_pass(self, n), y, x);
 #endif
     else
       res = sexp_type_exception(ctx, "bitwise-xor: not an integer", y);
@@ -129,7 +129,7 @@ static sexp sexp_bit_xor (sexp ctx, sexp x, sexp y) {
 
 /* should probably split into left and right shifts, that's a better */
 /* interface anyway */
-static sexp sexp_arithmetic_shift (sexp ctx, sexp i, sexp count) {
+static sexp sexp_arithmetic_shift (sexp ctx sexp_api_params(self, n), sexp i, sexp count) {
   sexp_uint_t tmp;
   sexp_sint_t c;
 #if SEXP_USE_BIGNUMS
@@ -156,7 +156,7 @@ static sexp sexp_arithmetic_shift (sexp ctx, sexp i, sexp count) {
       } else {
         sexp_gc_preserve1(ctx, res);
         res = sexp_fixnum_to_bignum(ctx, i);
-        res = sexp_arithmetic_shift(ctx, res, count);
+        res = sexp_arithmetic_shift(ctx sexp_api_pass(self, n), res, count);
         sexp_gc_release1(ctx);
       }
 #endif
@@ -208,7 +208,7 @@ static sexp_uint_t bit_count (sexp_uint_t i) {
           >> (sizeof(i) - 1) * CHAR_BIT);
 }
 
-static sexp sexp_bit_count (sexp ctx, sexp x) {
+static sexp sexp_bit_count (sexp ctx sexp_api_params(self, n), sexp x) {
   sexp res;
   sexp_sint_t i;
 #if SEXP_USE_BIGNUMS
@@ -250,7 +250,7 @@ static sexp_uint_t integer_log2 (sexp_uint_t x) {
     return (t = x >> 8) ? 8 + log_table_256[t] : log_table_256[x];
 }
 
-static sexp sexp_integer_length (sexp ctx, sexp x) {
+static sexp sexp_integer_length (sexp ctx sexp_api_params(self, n), sexp x) {
   sexp_sint_t tmp;
 #if SEXP_USE_BIGNUMS
   sexp_sint_t hi;
@@ -269,7 +269,7 @@ static sexp sexp_integer_length (sexp ctx, sexp x) {
   }
 }
 
-static sexp sexp_bit_set_p (sexp ctx, sexp i, sexp x) {
+static sexp sexp_bit_set_p (sexp ctx sexp_api_params(self, n), sexp i, sexp x) {
 #if SEXP_USE_BIGNUMS
   sexp_uint_t pos;
 #endif
diff --git a/lib/srfi/69/hash.c b/lib/srfi/69/hash.c
index da28f079..ec0b1d30 100644
--- a/lib/srfi/69/hash.c
+++ b/lib/srfi/69/hash.c
@@ -23,7 +23,7 @@ static sexp_uint_t string_hash (char *str, sexp_uint_t bound) {
   return acc % bound;
 }
 
-static sexp sexp_string_hash (sexp ctx, sexp str, sexp bound) {
+static sexp sexp_string_hash (sexp ctx sexp_api_params(self, n), sexp str, sexp bound) {
   if (! sexp_stringp(str))
     return sexp_type_exception(ctx, "string-hash: not a string", str);
   else if (! sexp_integerp(bound))
@@ -38,7 +38,7 @@ static sexp_uint_t string_ci_hash (char *str, sexp_uint_t bound) {
   return acc % bound;
 }
 
-static sexp sexp_string_ci_hash (sexp ctx, sexp str, sexp bound) {
+static sexp sexp_string_ci_hash (sexp ctx sexp_api_params(self, n), sexp str, sexp bound) {
   if (! sexp_stringp(str))
     return sexp_type_exception(ctx, "string-ci-hash: not a string", str);
   else if (! sexp_integerp(bound))
@@ -89,13 +89,13 @@ static sexp_uint_t hash_one (sexp ctx, sexp obj, sexp_uint_t bound, sexp_sint_t
   return (bound ? acc % bound : acc);
 }
 
-static sexp sexp_hash (sexp ctx, sexp obj, sexp bound) {
+static sexp sexp_hash (sexp ctx sexp_api_params(self, n), sexp obj, sexp bound) {
   if (! sexp_exact_integerp(bound))
     return sexp_type_exception(ctx, "hash: not an integer", bound);
   return sexp_make_fixnum(hash_one(ctx, obj, sexp_unbox_fixnum(bound), HASH_DEPTH));
 }
 
-static sexp sexp_hash_by_identity (sexp ctx, sexp obj, sexp bound) {
+static sexp sexp_hash_by_identity (sexp ctx sexp_api_params(self, n), sexp obj, sexp bound) {
   if (! sexp_exact_integerp(bound))
     return sexp_type_exception(ctx, "hash-by-identity: not an integer", bound);
   return sexp_make_fixnum((sexp_uint_t)obj % sexp_unbox_fixnum(bound));
@@ -106,9 +106,9 @@ static sexp sexp_get_bucket (sexp ctx, sexp buckets, sexp hash_fn, sexp obj) {
   sexp res;
   sexp_uint_t len = sexp_vector_length(buckets);
   if (hash_fn == sexp_make_fixnum(1))
-    res = sexp_hash_by_identity(ctx, obj, sexp_make_fixnum(len));
+    res = sexp_hash_by_identity(ctx sexp_api_pass(NULL, 2), obj, sexp_make_fixnum(len));
   else if (hash_fn == sexp_make_fixnum(2))
-    res = sexp_hash(ctx, obj, sexp_make_fixnum(len));
+    res = sexp_hash(ctx sexp_api_pass(NULL, 2), obj, sexp_make_fixnum(len));
   else {
     sexp_gc_preserve1(ctx, args);
     args = sexp_list2(ctx, obj, sexp_make_fixnum(len));
@@ -180,7 +180,7 @@ static void sexp_regrow_hash_table (sexp ctx, sexp ht, sexp oldbuckets, sexp has
   sexp_gc_release1(ctx);
 }
 
-static sexp sexp_hash_table_cell (sexp ctx, sexp ht, sexp obj, sexp createp) {
+static sexp sexp_hash_table_cell (sexp ctx sexp_api_params(self, n), sexp ht, sexp obj, sexp createp) {
   sexp buckets, eq_fn, hash_fn, i;
   sexp_uint_t size;
   sexp_gc_var1(res);
@@ -209,7 +209,7 @@ static sexp sexp_hash_table_cell (sexp ctx, sexp ht, sexp obj, sexp createp) {
   return res;
 }
 
-static sexp sexp_hash_table_delete (sexp ctx, sexp ht, sexp obj) {
+static sexp sexp_hash_table_delete (sexp ctx sexp_api_params(self, n), sexp ht, sexp obj) {
   sexp buckets=sexp_hash_table_buckets(ht), eq_fn=sexp_hash_table_eq_fn(ht),
     hash_fn=sexp_hash_table_hash_fn(ht), i, p, res;
   i = sexp_get_bucket(ctx, buckets, hash_fn, obj);
diff --git a/lib/srfi/95/qsort.c b/lib/srfi/95/qsort.c
index 1cfdbe24..970f36b4 100644
--- a/lib/srfi/95/qsort.c
+++ b/lib/srfi/95/qsort.c
@@ -134,7 +134,8 @@ static sexp sexp_qsort_less (sexp ctx, sexp *vec,
   return res;
 }
 
-static sexp sexp_sort_x (sexp ctx, sexp seq, sexp less, sexp key) {
+static sexp sexp_sort_x (sexp ctx sexp_api_params(self, n), sexp seq,
+                         sexp less, sexp key) {
   sexp_sint_t len;
   sexp res, *data;
   sexp_gc_var1(vec);
diff --git a/sexp.c b/sexp.c
index f4f3d46c..1f7c3468 100644
--- a/sexp.c
+++ b/sexp.c
@@ -122,9 +122,9 @@ static sexp_uint_t sexp_type_array_size = SEXP_NUM_CORE_TYPES;
 #define SEXP_INIT_NUM_TYPES (SEXP_NUM_CORE_TYPES*2)
 #endif
 
-sexp sexp_register_type (sexp ctx, sexp name, sexp fb, sexp felb, sexp flb,
-                         sexp flo, sexp fls, sexp sb, sexp so, sexp sc,
-                         sexp_proc2 f) {
+sexp sexp_register_type_op (sexp ctx sexp_api_params(self, n), sexp name,
+                            sexp fb, sexp felb, sexp flb, sexp flo, sexp fls,
+                            sexp sb, sexp so, sexp sc, sexp_proc2 f) {
 #if SEXP_USE_GLOBAL_TYPES
   struct sexp_struct *new, *tmp;
 #else