diff --git a/NEWS b/NEWS
index acf414caa2..f1f7e66758 100644
--- a/NEWS
+++ b/NEWS
@@ -105,3 +105,5 @@ with all sufficient information, see the ChangeLog file.
 
 * struct RSymbol added. This represents a dynamic symbol as object in
   Ruby's heaps.
+
+* rb_str_cat_cstr() added. This is same as `rb_str_cat2()`.
diff --git a/README.EXT b/README.EXT
index b36273723d..6ba0e6fec6 100644
--- a/README.EXT
+++ b/README.EXT
@@ -208,6 +208,7 @@ rb_str_cat(VALUE str, const char *ptr, long len) ::
   Appends len bytes of data from ptr to the Ruby string.
 
 rb_str_cat2(VALUE str, const char* ptr) ::
+rb_str_cat_cstr(VALUE str, const char* ptr) ::
 
   Appends C string ptr to Ruby string str.  This function is
   equivalent to rb_str_cat(str, ptr, strlen(ptr)).
diff --git a/README.EXT.ja b/README.EXT.ja
index d18b81b58e..5a0073e977 100644
--- a/README.EXT.ja
+++ b/README.EXT.ja
@@ -234,6 +234,7 @@ rb_str_cat(VALUE str, const char *ptr, long len)
   Rubyの文字列strにlenバイトの文字列ptrを追加する．
 
 rb_str_cat2(VALUE str, const char* ptr)
+rb_str_cat_cstr(VALUE str, const char* ptr)
 
   Rubyの文字列strにCの文字列ptrを追加する．この関数の機能は
   rb_str_cat(str, ptr, strlen(ptr))と同等である．
diff --git a/include/ruby/intern.h b/include/ruby/intern.h
index 26b880e022..c69d378f62 100644
--- a/include/ruby/intern.h
+++ b/include/ruby/intern.h
@@ -727,6 +727,7 @@ VALUE rb_str_freeze(VALUE);
 void rb_str_set_len(VALUE, long);
 VALUE rb_str_resize(VALUE, long);
 VALUE rb_str_cat(VALUE, const char*, long);
+VALUE rb_str_cat_cstr(VALUE, const char*);
 VALUE rb_str_cat2(VALUE, const char*);
 VALUE rb_str_append(VALUE, VALUE);
 VALUE rb_str_concat(VALUE, VALUE);
@@ -798,17 +799,11 @@ VALUE rb_str_scrub(VALUE, VALUE);
 		       (str), (long)strlen(str)) : \
 	rb_str_buf_new_cstr(str);		\
 })
-#define rb_str_buf_cat2(str, ptr) __extension__ ( \
-{						\
-    (__builtin_constant_p(ptr)) ?	        \
-	rb_str_buf_cat((str), (ptr), (long)strlen(ptr)) : \
-	rb_str_buf_cat2((str), (ptr));		\
-})
-#define rb_str_cat2(str, ptr) __extension__ (	\
+#define rb_str_cat_cstr(str, ptr) __extension__ ( \
 {						\
     (__builtin_constant_p(ptr)) ?	        \
 	rb_str_cat((str), (ptr), (long)strlen(ptr)) : \
-	rb_str_cat2((str), (ptr));			\
+	rb_str_cat_cstr((str), (ptr));		\
 })
 #define rb_exc_new_cstr(klass, ptr) __extension__ ( \
 {						\
@@ -824,6 +819,9 @@ VALUE rb_str_scrub(VALUE, VALUE);
 #define rb_tainted_str_new2 rb_tainted_str_new_cstr
 #define rb_str_buf_new2 rb_str_buf_new_cstr
 #define rb_usascii_str_new2 rb_usascii_str_new_cstr
+#define rb_str_buf_cat rb_str_cat
+#define rb_str_buf_cat2 rb_str_cat_cstr
+#define rb_str_cat2 rb_str_cat_cstr
 /* struct.c */
 VALUE rb_struct_new(VALUE, ...);
 VALUE rb_struct_define(const char*, ...);
diff --git a/string.c b/string.c
index 3ad5eedbd1..3845430cec 100644
--- a/string.c
+++ b/string.c
@@ -38,8 +38,10 @@
 #undef rb_locale_str_new_cstr
 #undef rb_str_dup_frozen
 #undef rb_str_buf_new_cstr
+#undef rb_str_buf_cat
 #undef rb_str_buf_cat2
 #undef rb_str_cat2
+#undef rb_str_cat_cstr
 
 static VALUE rb_str_clear(VALUE str);
 
@@ -2048,7 +2050,7 @@ str_buf_cat(VALUE str, const char *ptr, long len)
 #define str_buf_cat2(str, ptr) str_buf_cat((str), (ptr), strlen(ptr))
 
 VALUE
-rb_str_buf_cat(VALUE str, const char *ptr, long len)
+rb_str_cat(VALUE str, const char *ptr, long len)
 {
     if (len == 0) return str;
     if (len < 0) {
@@ -2058,13 +2060,14 @@ rb_str_buf_cat(VALUE str, const char *ptr, long len)
 }
 
 VALUE
-rb_str_buf_cat2(VALUE str, const char *ptr)
+rb_str_cat_cstr(VALUE str, const char *ptr)
 {
     return rb_str_buf_cat(str, ptr, strlen(ptr));
 }
 
-RUBY_ALIAS_FUNCTION(rb_str_cat(VALUE str, const char *ptr, long len), rb_str_buf_cat, (str, ptr, len))
-RUBY_ALIAS_FUNCTION(rb_str_cat2(VALUE str, const char *ptr), rb_str_buf_cat2, (str, ptr))
+RUBY_ALIAS_FUNCTION(rb_str_buf_cat(VALUE str, const char *ptr, long len), rb_str_cat, (str, ptr, len))
+RUBY_ALIAS_FUNCTION(rb_str_buf_cat2(VALUE str, const char *ptr), rb_str_cat_cstr, (str, ptr))
+RUBY_ALIAS_FUNCTION(rb_str_cat2(VALUE str, const char *ptr), rb_str_cat_cstr, (str, ptr))
 
 static VALUE
 rb_enc_cr_str_buf_cat(VALUE str, const char *ptr, long len,