diff --git a/racket/src/cs/c/boot.c b/racket/src/cs/c/boot.c
index 909bd322b4..4cb2a27e2e 100644
--- a/racket/src/cs/c/boot.c
+++ b/racket/src/cs/c/boot.c
@@ -164,10 +164,10 @@ void racket_boot(racket_boot_arguments_t *ba)
     l = Scons(Sbytevector(ba->cs_compiled_subdir ? "true" : "false"), l);
     sprintf(segment_offset_s, "%ld", ba->segment_offset);
     l = Scons(Sbytevector(segment_offset_s), l);
-    l = Scons(Sbytevector(ba->config_dir ? ba->config_dir : "etc"), l);
-    l = Scons(parse_coldirs(ba->collects_dir ? ba->collects_dir : ""), l);
-    l = Scons(Sbytevector(ba->run_file ? ba->run_file : ba->exec_file ), l);
-    l = Scons(Sbytevector(ba->exec_file), l);
+    l = Scons(Sbytevector(ba->config_dir ? (char *)ba->config_dir : "etc"), l);
+    l = Scons(parse_coldirs(ba->collects_dir ? (char *)ba->collects_dir : ""), l);
+    l = Scons(Sbytevector(ba->run_file ? (char *)ba->run_file : (char *)ba->exec_file ), l);
+    l = Scons(Sbytevector((char *)ba->exec_file), l);
     l = Scons(Sbytevector(ba->exit_after ? "false" : "true"), l);
 
 #ifdef RACKET_AS_BOOT