diff --git a/parse.y b/parse.y
index 1631bdecc2bf36..36803394fdde8f 100644
--- a/parse.y
+++ b/parse.y
@@ -7637,7 +7637,7 @@ yycompile(struct parser_params *p, VALUE fname, int line)
         p->ruby_sourcefile = "(none)";
     }
     else {
-        p->ruby_sourcefile_string = rb_fstring(fname);
+        p->ruby_sourcefile_string = rb_str_to_interned_str(fname);
         p->ruby_sourcefile = StringValueCStr(fname);
     }
     p->ruby_sourceline = line - 1;
@@ -13485,7 +13485,7 @@ rb_parser_trace_lex_state(struct parser_params *p, enum lex_state_e from,
 VALUE
 rb_parser_lex_state_name(struct parser_params *p, enum lex_state_e state)
 {
-    return rb_fstring(append_lex_state_name(p, state, rb_str_new(0, 0)));
+    return rb_str_to_interned_str(append_lex_state_name(p, state, rb_str_new(0, 0)));
 }
 
 static void
@@ -14026,13 +14026,13 @@ shareable_literal_constant(struct parser_params *p, enum shareability shareable,
         return value;
 
       case NODE_STR:
-        lit = rb_fstring(rb_node_str_string_val(value));
+        lit = rb_str_to_interned_str(rb_node_str_string_val(value));
         value = NEW_LIT(lit, loc);
         RB_OBJ_WRITE(p->ast, &RNODE_LIT(value)->nd_lit, lit);
         return value;
 
       case NODE_FILE:
-        lit = rb_fstring(rb_node_file_path_val(value));
+        lit = rb_str_to_interned_str(rb_node_file_path_val(value));
         value = NEW_LIT(lit, loc);
         RB_OBJ_WRITTEN(p->ast, Qnil, RNODE_LIT(value)->nd_lit);
         return value;
diff --git a/ruby_parser.c b/ruby_parser.c
index c4b4ffc1a319f6..8e2371fd1d92dd 100644
--- a/ruby_parser.c
+++ b/ruby_parser.c
@@ -533,7 +533,7 @@ static const rb_parser_config_t rb_global_parser_config = {
     .str_resize = rb_str_resize,
     .str_new = rb_str_new,
     .str_new_cstr = rb_str_new_cstr,
-    .fstring = rb_fstring,
+    .str_to_interned_str = rb_str_to_interned_str,
     .is_ascii_string = is_ascii_string2,
     .enc_str_new = enc_str_new,
     .enc_str_buf_cat = enc_str_buf_cat,
diff --git a/rubyparser.h b/rubyparser.h
index ab8a39367d4a5e..34ee117f650974 100644
--- a/rubyparser.h
+++ b/rubyparser.h
@@ -1272,7 +1272,7 @@ typedef struct rb_parser_config_struct {
     VALUE (*str_resize)(VALUE str, long len);
     VALUE (*str_new)(const char *ptr, long len);
     VALUE (*str_new_cstr)(const char *ptr);
-    VALUE (*fstring)(VALUE);
+    VALUE (*str_to_interned_str)(VALUE);
     int (*is_ascii_string)(VALUE str);
     VALUE (*enc_str_new)(const char *ptr, long len, rb_encoding *enc);
     VALUE (*enc_str_buf_cat)(VALUE str, const char *ptr, long len, rb_encoding *enc);
diff --git a/universal_parser.c b/universal_parser.c
index a3edbb92472ba6..2cd5c7407badc5 100644
--- a/universal_parser.c
+++ b/universal_parser.c
@@ -157,7 +157,7 @@ struct rb_imemo_tmpbuf_struct {
 #define rb_str_new                        p->config->str_new
 #undef rb_str_new_cstr
 #define rb_str_new_cstr                   p->config->str_new_cstr
-#define rb_fstring                        p->config->fstring
+#define rb_str_to_interned_str            p->config->str_to_interned_str
 #define is_ascii_string                   p->config->is_ascii_string
 #define rb_enc_str_new                    p->config->enc_str_new
 #define rb_enc_str_buf_cat                p->config->enc_str_buf_cat