diff --git a/lib/chibi/ast.c b/lib/chibi/ast.c
index 915b77f1..c071436c 100644
--- a/lib/chibi/ast.c
+++ b/lib/chibi/ast.c
@@ -12,7 +12,7 @@
 extern sexp sexp_gc (sexp ctx, size_t *sum_freed);
 #endif
 
-static void sexp_define_type_predicate (sexp ctx, sexp env, char *cname, sexp_uint_t type) {
+static void sexp_define_type_predicate (sexp ctx, sexp env, const char *cname, sexp_uint_t type) {
   sexp_gc_var2(name, op);
   sexp_gc_preserve2(ctx, name, op);
   name = sexp_c_string(ctx, cname, -1);
@@ -22,7 +22,8 @@ static void sexp_define_type_predicate (sexp ctx, sexp env, char *cname, sexp_ui
 }
 
 static void sexp_define_accessors (sexp ctx, sexp env, sexp_uint_t ctype,
-                                   sexp_uint_t cindex, char* get, char *set) {
+                                   sexp_uint_t cindex,
+                                   const char* get, const char *set) {
   sexp type, index;
   sexp_gc_var2(name, op);
   sexp_gc_preserve2(ctx, name, op);
@@ -480,7 +481,7 @@ static sexp sexp_unsetenv (sexp ctx, sexp self, sexp_sint_t n, sexp name) {
 #define sexp_define_type(ctx, name, tag) \
   sexp_env_define(ctx, env, sexp_intern(ctx, name, -1), sexp_type_by_index(ctx, tag));
 
-sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, sexp_abi_identifier_t abi) {
+sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, const sexp_abi_identifier_t abi) {
   if (!(sexp_version_compatible(ctx, version, sexp_version)
         && sexp_abi_compatible(ctx, abi, SEXP_ABI_IDENTIFIER)))
     return SEXP_ABI_ERROR;
diff --git a/lib/chibi/disasm.c b/lib/chibi/disasm.c
index 1f2e8110..a364266a 100644
--- a/lib/chibi/disasm.c
+++ b/lib/chibi/disasm.c
@@ -231,7 +231,7 @@ static sexp sexp_disasm (sexp ctx, sexp self, sexp_sint_t n, sexp bc, sexp out)
   return disasm(ctx, self, bc, out, 0);
 }
 
-sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, sexp_abi_identifier_t abi) {
+sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, const sexp_abi_identifier_t abi) {
   if (!(sexp_version_compatible(ctx, version, sexp_version)
         && sexp_abi_compatible(ctx, abi, SEXP_ABI_IDENTIFIER)))
     return SEXP_ABI_ERROR;
diff --git a/lib/chibi/heap-stats.c b/lib/chibi/heap-stats.c
index 2f61bc6a..921cf401 100644
--- a/lib/chibi/heap-stats.c
+++ b/lib/chibi/heap-stats.c
@@ -128,7 +128,7 @@ static sexp sexp_heap_dump (sexp ctx, sexp self, sexp_sint_t n, sexp depth) {
 
 #endif
 
-sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, sexp_abi_identifier_t abi) {
+sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, const sexp_abi_identifier_t abi) {
   if (!(sexp_version_compatible(ctx, version, sexp_version)
         && sexp_abi_compatible(ctx, abi, SEXP_ABI_IDENTIFIER)))
     return SEXP_ABI_ERROR;
diff --git a/lib/chibi/io/port.c b/lib/chibi/io/port.c
index 55173aa1..e3c80f06 100644
--- a/lib/chibi/io/port.c
+++ b/lib/chibi/io/port.c
@@ -2,6 +2,10 @@
 #include <stdio.h>
 #include <chibi/eval.h>
 
+#if SEXP_USE_SEND_FILE
+#include <sys/sendfile.h>
+#endif
+
 #define SEXP_LAST_CONTEXT_CHECK_LIMIT 256
 
 #define sexp_cookie_ctx(vec) sexp_vector_ref((sexp)vec, SEXP_ZERO)
@@ -144,7 +148,7 @@ static cookie_io_functions_t sexp_cookie_no_seek = {
 
 #endif  /* !SEXP_BSD */
 
-static sexp sexp_make_custom_port (sexp ctx, sexp self, char *mode,
+static sexp sexp_make_custom_port (sexp ctx, sexp self, const char *mode,
                                    sexp read, sexp write,
                                    sexp seek, sexp close) {
   FILE *in;
@@ -190,7 +194,7 @@ static sexp sexp_make_custom_port (sexp ctx, sexp self, char *mode,
 #else  /* ! SEXP_USE_STRING_STREAMS */
 
 static sexp sexp_make_custom_port (sexp ctx, sexp self,
-                                   char *mode, sexp read, sexp write,
+                                   const char *mode, sexp read, sexp write,
                                    sexp seek, sexp close) {
   sexp vec;
   sexp_gc_var2(res, str);
diff --git a/lib/chibi/optimize/profile.c b/lib/chibi/optimize/profile.c
index 5fc4bb60..929a9d97 100644
--- a/lib/chibi/optimize/profile.c
+++ b/lib/chibi/optimize/profile.c
@@ -10,7 +10,7 @@ static sexp sexp_increment_cdr (sexp ctx, sexp self, sexp_sint_t n, sexp pair) {
   return SEXP_VOID;
 }
 
-sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, sexp_abi_identifier_t abi) {
+sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, const sexp_abi_identifier_t abi) {
   if (!(sexp_version_compatible(ctx, version, sexp_version)
         && sexp_abi_compatible(ctx, abi, SEXP_ABI_IDENTIFIER)))
     return SEXP_ABI_ERROR;
diff --git a/lib/chibi/optimize/rest.c b/lib/chibi/optimize/rest.c
index fbdcd417..96db0fdb 100644
--- a/lib/chibi/optimize/rest.c
+++ b/lib/chibi/optimize/rest.c
@@ -19,7 +19,7 @@ static sexp copy_opcode (sexp ctx, struct sexp_opcode_struct *op) {
   return res;
 }
 
-sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, sexp_abi_identifier_t abi) {
+sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, const sexp_abi_identifier_t abi) {
   sexp_gc_var2(name, op);
   if (!(sexp_version_compatible(ctx, version, sexp_version)
         && sexp_abi_compatible(ctx, abi, SEXP_ABI_IDENTIFIER)))
diff --git a/lib/chibi/weak.c b/lib/chibi/weak.c
index f520fd92..71cfbd69 100644
--- a/lib/chibi/weak.c
+++ b/lib/chibi/weak.c
@@ -59,7 +59,7 @@ sexp sexp_weak_vector_set (sexp ctx, sexp self, sexp_sint_t n, sexp v, sexp k, s
   return SEXP_VOID;
 }
 
-sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, sexp_abi_identifier_t abi) {
+sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, const sexp_abi_identifier_t abi) {
 #if 0
   sexp v;
   int sexp_weak_vector_id;
diff --git a/lib/scheme/time.c b/lib/scheme/time.c
index 1a8a6ab6..6d676a8e 100644
--- a/lib/scheme/time.c
+++ b/lib/scheme/time.c
@@ -93,7 +93,7 @@ static sexp sexp_current_clock_second (sexp ctx, sexp self, sexp_sint_t n) {
 #endif
 }
 
-sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, sexp_abi_identifier_t abi) {
+sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, const sexp_abi_identifier_t abi) {
   if (!(sexp_version_compatible(ctx, version, sexp_version)
         && sexp_abi_compatible(ctx, abi, SEXP_ABI_IDENTIFIER)))
     return sexp_global(ctx, SEXP_G_ABI_ERROR);
diff --git a/lib/srfi/18/threads.c b/lib/srfi/18/threads.c
index 76f39e6b..e5e11503 100644
--- a/lib/srfi/18/threads.c
+++ b/lib/srfi/18/threads.c
@@ -629,7 +629,7 @@ sexp sexp_lookup_named_type (sexp ctx, sexp env, const char *name) {
 
 #endif  /* SEXP_USE_GREEN_THREADS */
 
-sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, sexp_abi_identifier_t abi) {
+sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, const sexp_abi_identifier_t abi) {
   sexp t;
   sexp_gc_var1(name);
   if (!(sexp_version_compatible(ctx, version, sexp_version)
diff --git a/lib/srfi/27/rand.c b/lib/srfi/27/rand.c
index 8dd0d8de..28ab79a6 100644
--- a/lib/srfi/27/rand.c
+++ b/lib/srfi/27/rand.c
@@ -169,7 +169,7 @@ static sexp sexp_random_source_pseudo_randomize (sexp ctx, sexp self, sexp_sint_
   return SEXP_VOID;
 }
 
-sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, sexp_abi_identifier_t abi) {
+sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, const sexp_abi_identifier_t abi) {
   sexp_gc_var2(name, op);
   if (!(sexp_version_compatible(ctx, version, sexp_version)
         && sexp_abi_compatible(ctx, abi, SEXP_ABI_IDENTIFIER)))
diff --git a/lib/srfi/33/bit.c b/lib/srfi/33/bit.c
index 995d4da7..1baaaf46 100644
--- a/lib/srfi/33/bit.c
+++ b/lib/srfi/33/bit.c
@@ -311,7 +311,7 @@ static sexp sexp_bit_set_p (sexp ctx, sexp self, sexp_sint_t n, sexp i, sexp x)
   }
 }
 
-sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, sexp_abi_identifier_t abi) {
+sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, const sexp_abi_identifier_t abi) {
   if (!(sexp_version_compatible(ctx, version, sexp_version)
         && sexp_abi_compatible(ctx, abi, SEXP_ABI_IDENTIFIER)))
     return SEXP_ABI_ERROR;
diff --git a/lib/srfi/39/param.c b/lib/srfi/39/param.c
index 5cd1c90c..01c477db 100644
--- a/lib/srfi/39/param.c
+++ b/lib/srfi/39/param.c
@@ -26,7 +26,7 @@ static sexp sexp_parameter_converter (sexp ctx, sexp self, sexp_sint_t n, sexp p
   return res ? res : SEXP_FALSE;
 }
 
-sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, sexp_abi_identifier_t abi) {
+sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, const sexp_abi_identifier_t abi) {
   if (!(sexp_version_compatible(ctx, version, sexp_version)
         && sexp_abi_compatible(ctx, abi, SEXP_ABI_IDENTIFIER)))
     return SEXP_ABI_ERROR;
diff --git a/lib/srfi/69/hash.c b/lib/srfi/69/hash.c
index 30816072..13987c36 100644
--- a/lib/srfi/69/hash.c
+++ b/lib/srfi/69/hash.c
@@ -236,7 +236,7 @@ static sexp sexp_hash_table_delete (sexp ctx, sexp self, sexp_sint_t n, sexp ht,
   return SEXP_VOID;
 }
 
-sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, sexp_abi_identifier_t abi) {
+sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, const sexp_abi_identifier_t abi) {
   if (!(sexp_version_compatible(ctx, version, sexp_version)
         && sexp_abi_compatible(ctx, abi, SEXP_ABI_IDENTIFIER)))
     return SEXP_ABI_ERROR;
diff --git a/lib/srfi/95/qsort.c b/lib/srfi/95/qsort.c
index 799fa105..60970bb2 100644
--- a/lib/srfi/95/qsort.c
+++ b/lib/srfi/95/qsort.c
@@ -256,7 +256,7 @@ static sexp sexp_sort_x (sexp ctx, sexp self, sexp_sint_t n, sexp seq,
   return res;
 }
 
-sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, sexp_abi_identifier_t abi) {
+sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, const sexp_abi_identifier_t abi) {
   if (!(sexp_version_compatible(ctx, version, sexp_version)
         && sexp_abi_compatible(ctx, abi, SEXP_ABI_IDENTIFIER)))
     return SEXP_ABI_ERROR;
diff --git a/lib/srfi/98/env.c b/lib/srfi/98/env.c
index 486d5fe8..e583ab70 100644
--- a/lib/srfi/98/env.c
+++ b/lib/srfi/98/env.c
@@ -44,7 +44,7 @@ sexp sexp_get_environment_variables (sexp ctx, sexp self, sexp_sint_t n) {
   return res;
 }
 
-sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, sexp_abi_identifier_t abi) {
+sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, const sexp_abi_identifier_t abi) {
   if (!(sexp_version_compatible(ctx, version, sexp_version)
         && sexp_abi_compatible(ctx, abi, SEXP_ABI_IDENTIFIER)))
     return SEXP_ABI_ERROR;
diff --git a/tools/chibi-ffi b/tools/chibi-ffi
index 2cdd1b2a..ff00bdcb 100755
--- a/tools/chibi-ffi
+++ b/tools/chibi-ffi
@@ -1707,7 +1707,7 @@
   (newline)
   (if *c++?*
       (cat "extern \"C\" "))
-  (cat "sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, sexp_abi_identifier_t abi) {\n"
+  (cat "sexp sexp_init_library (sexp ctx, sexp self, sexp_sint_t n, sexp env, const char* version, const sexp_abi_identifier_t abi) {\n"
        (lambda ()
          (for-each
           (lambda (t) (cat "  sexp " t ";\n"))