diff --git a/include/ruby/ruby.h b/include/ruby/ruby.h
index 9b7c9842f8..1853c6348d 100644
--- a/include/ruby/ruby.h
+++ b/include/ruby/ruby.h
@@ -1957,6 +1957,7 @@ PRINTF_ARGS(void rb_compile_warning(const char *, int, const char*, ...), 3, 4);
 PRINTF_ARGS(void rb_sys_warning(const char*, ...), 1, 2);
 /* reports always */
 COLDFUNC PRINTF_ARGS(void rb_warn(const char*, ...), 1, 2);
+PRINTF_ARGS(void rb_warn_deprecated(const char *fmt, const char *suggest, ...), 1, 3);
 PRINTF_ARGS(void rb_compile_warn(const char *, int, const char*, ...), 3, 4);
 
 #define RB_BLOCK_CALL_FUNC_STRICT 1
@@ -2569,7 +2570,7 @@ rb_scan_args_set(int argc, const VALUE *argv,
                     if (!keyword_given) {
                         /* Warn if treating positional as keyword, as in Ruby 3,
                            this will be an error */
-                        rb_warn("Using the last argument as keyword parameters is deprecated");
+                        rb_warn_deprecated("Using the last argument as keyword parameters", NULL);
                     }
                     argc--;
                 }
@@ -2584,7 +2585,7 @@ rb_scan_args_set(int argc, const VALUE *argv,
         }
         else if (f_hash && keyword_given && n_mand == argc) {
             /* Warn if treating keywords as positional, as in Ruby 3, this will be an error */
-            rb_warn("Passing the keyword argument as the last hash parameter is deprecated");
+            rb_warn_deprecated("Passing the keyword argument as the last hash parameter", NULL);
         }
     }
     if (f_hash && n_mand > 0 && n_mand == argc+1 && empty_keyword_given) {
@@ -2593,7 +2594,7 @@ rb_scan_args_set(int argc, const VALUE *argv,
         ptr[argc] = rb_hash_new();
         argc++;
         *(&argv) = ptr;
-        rb_warn("Passing the keyword argument as the last hash parameter is deprecated");
+        rb_warn_deprecated("Passing the keyword argument as the last hash parameter", NULL);
     }
 
 
diff --git a/internal.h b/internal.h
index d5f1b93b39..663d4d68ea 100644
--- a/internal.h
+++ b/internal.h
@@ -1549,7 +1549,6 @@ void rb_report_bug_valist(VALUE file, int line, const char *fmt, va_list args);
 NORETURN(void rb_async_bug_errno(const char *,int));
 const char *rb_builtin_type_name(int t);
 const char *rb_builtin_class_name(VALUE x);
-PRINTF_ARGS(void rb_warn_deprecated(const char *fmt, const char *suggest, ...), 1, 3);
 #ifdef RUBY_ENCODING_H
 VALUE rb_syntax_error_append(VALUE, VALUE, int, int, rb_encoding*, const char*, va_list);
 PRINTF_ARGS(void rb_enc_warn(rb_encoding *enc, const char *fmt, ...), 2, 3);