diff --git a/eval_intern.h b/eval_intern.h
index b945848a7a..cf7fb23197 100644
--- a/eval_intern.h
+++ b/eval_intern.h
@@ -110,16 +110,16 @@ extern int select_large_fdset(int, fd_set *, fd_set *, fd_set *, struct timeval
 
 /* clear th->state, and return the value */
 static inline int
-ruby_threadptr_tag_state(rb_thread_t *th)
+rb_threadptr_tag_state(rb_thread_t *th)
 {
     int state = th->state;
     th->state = 0;
     return state;
 }
 
-NORETURN(static inline void ruby_threadptr_tag_jump(rb_thread_t *, int));
+NORETURN(static inline void rb_threadptr_tag_jump(rb_thread_t *, int));
 static inline void
-ruby_threadptr_tag_jump(rb_thread_t *th, int st)
+rb_threadptr_tag_jump(rb_thread_t *th, int st)
 {
     ruby_longjmp(th->tag->buf, (th->state = st));
 }
@@ -129,12 +129,12 @@ ruby_threadptr_tag_jump(rb_thread_t *th, int st)
   [ISO/IEC 9899:1999] 7.13.1.1
 */
 #define TH_EXEC_TAG() \
-    (ruby_setjmp(_th->tag->buf) ? ruby_threadptr_tag_state(_th) : 0)
+    (ruby_setjmp(_th->tag->buf) ? rb_threadptr_tag_state(_th) : 0)
 
 #define EXEC_TAG() \
   TH_EXEC_TAG()
 
-#define TH_JUMP_TAG(th, st) ruby_threadptr_tag_jump(th, st)
+#define TH_JUMP_TAG(th, st) rb_threadptr_tag_jump(th, st)
 
 #define JUMP_TAG(st) TH_JUMP_TAG(GET_THREAD(), (st))