diff --git a/racket/src/racket/src/port.c b/racket/src/racket/src/port.c
index 0b69cf9a58..d4ed339614 100644
--- a/racket/src/racket/src/port.c
+++ b/racket/src/racket/src/port.c
@@ -174,8 +174,6 @@ THREAD_LOCAL_DECL(Scheme_Object *scheme_orig_stdout_port);
 THREAD_LOCAL_DECL(Scheme_Object *scheme_orig_stderr_port);
 THREAD_LOCAL_DECL(Scheme_Object *scheme_orig_stdin_port);
 
-THREAD_LOCAL_DECL(struct mz_fd_set *scheme_semaphore_fd_set);
-
 HOOK_SHARED_OK Scheme_Object *(*scheme_make_stdin)(void) = NULL;
 HOOK_SHARED_OK Scheme_Object *(*scheme_make_stdout)(void) = NULL;
 HOOK_SHARED_OK Scheme_Object *(*scheme_make_stderr)(void) = NULL;
@@ -188,7 +186,7 @@ THREAD_LOCAL_DECL(static int special_is_ok);
 /* locals */
 
 THREAD_LOCAL_DECL(static int fd_reserved);
-THREAD_LOCAL_DECL(static int the_fd);
+THREAD_LOCAL_DECL(static rktio_fd_t *the_fd);
 
 READ_ONLY static Scheme_Object *fd_input_port_type;
 READ_ONLY static Scheme_Object *file_input_port_type;
@@ -212,9 +210,6 @@ SHARED_OK static int flush_err;
 
 THREAD_LOCAL_DECL(static Scheme_Custodian *new_port_cust); /* back-door argument */
 
-THREAD_LOCAL_DECL(static int external_event_fd);
-THREAD_LOCAL_DECL(static int put_external_event_fd);
-
 static void register_port_wait();
 
 static intptr_t flush_fd(Scheme_Output_Port *op,
diff --git a/racket/src/racket/src/schpriv.h b/racket/src/racket/src/schpriv.h
index 7213983e44..e6989a98e3 100644
--- a/racket/src/racket/src/schpriv.h
+++ b/racket/src/racket/src/schpriv.h
@@ -215,7 +215,7 @@ Scheme_Object *scheme_dump_gc_stats(int c, Scheme_Object *p[]);
 
 #define REGISTER_SO(x) MZ_REGISTER_STATIC(x)
 
-THREAD_LOCAL_DECL(extern struct rktio_t *rktio);
+THREAD_LOCAL_DECL(extern struct rktio_t *scheme_rktio);
 THREAD_LOCAL_DECL(extern int scheme_current_place_id);
 THREAD_LOCAL_DECL(extern intptr_t scheme_total_gc_time);
 THREAD_LOCAL_DECL(extern int scheme_cont_capture_count);
@@ -4335,7 +4335,7 @@ void scheme_rktio_socket_to_output_port(struct rktio_fd_t *fd, Scheme_Object *na
 
 void scheme_fs_change_properties(int *_supported, int *_scalable, int *_low_latency, int *_file_level);
 
-THREAD_LOCAL_DECL(extern struct mz_fd_set *scheme_semaphore_fd_set);
+THREAD_LOCAL_DECL(extern struct rktio_ltps_t *scheme_semaphore_fd_set);
 THREAD_LOCAL_DECL(extern Scheme_Hash_Table *scheme_semaphore_fd_mapping);
 
 intptr_t scheme_get_byte_string_or_ch_put(const char *who,