diff --git a/common.mk b/common.mk
index 4f3c0a9a08..ebbaf1aa6c 100644
--- a/common.mk
+++ b/common.mk
@@ -19522,6 +19522,7 @@ version.$(OBJEXT): $(top_srcdir)/internal/cmdlineopt.h
 version.$(OBJEXT): $(top_srcdir)/internal/compilers.h
 version.$(OBJEXT): $(top_srcdir)/internal/gc.h
 version.$(OBJEXT): $(top_srcdir)/internal/imemo.h
+version.$(OBJEXT): $(top_srcdir)/internal/parse.h
 version.$(OBJEXT): $(top_srcdir)/internal/sanitizers.h
 version.$(OBJEXT): $(top_srcdir)/internal/serial.h
 version.$(OBJEXT): $(top_srcdir)/internal/static_assert.h
diff --git a/internal/parse.h b/internal/parse.h
index e0c81f4f96..de42acbed9 100644
--- a/internal/parse.h
+++ b/internal/parse.h
@@ -13,11 +13,15 @@
 #include "internal/static_assert.h"
 
 // The default parser to use for Ruby code.
-// 0: parse.y
-// 1: Prism
-#ifndef RB_DEFAULT_PARSER
-#define RB_DEFAULT_PARSER 1
-#endif
+typedef enum {
+    RB_DEFAULT_PARSER_PARSE_Y,
+    RB_DEFAULT_PARSER_PRISM,
+} ruby_default_parser_enum;
+
+ruby_default_parser_enum rb_ruby_default_parser(void);
+void rb_ruby_default_parser_set(ruby_default_parser_enum parser);
+
+#define rb_ruby_prism_p() (rb_ruby_default_parser() == RB_DEFAULT_PARSER_PRISM)
 
 #ifdef UNIVERSAL_PARSER
 #define rb_encoding const void
diff --git a/iseq.c b/iseq.c
index 2c02043d55..d267c7e08b 100644
--- a/iseq.c
+++ b/iseq.c
@@ -1564,7 +1564,7 @@ iseqw_s_compile_parser(int argc, VALUE *argv, VALUE self, bool prism)
 static VALUE
 iseqw_s_compile(int argc, VALUE *argv, VALUE self)
 {
-    return iseqw_s_compile_parser(argc, argv, self, *rb_ruby_prism_ptr());
+    return iseqw_s_compile_parser(argc, argv, self, rb_ruby_prism_p());
 }
 
 /*
diff --git a/load.c b/load.c
index c6fb43e9e8..c1862c38fa 100644
--- a/load.c
+++ b/load.c
@@ -743,7 +743,7 @@ load_iseq_eval(rb_execution_context_t *ec, VALUE fname)
         rb_thread_t *th = rb_ec_thread_ptr(ec);
         VALUE realpath_map = get_loaded_features_realpath_map(th->vm);
 
-        if (*rb_ruby_prism_ptr()) {
+        if (rb_ruby_prism_p()) {
             pm_parse_result_t result = { 0 };
             result.options.line = 1;
             result.node.coverage_enabled = 1;
diff --git a/mini_builtin.c b/mini_builtin.c
index b9be7c58f8..2fbc00234d 100644
--- a/mini_builtin.c
+++ b/mini_builtin.c
@@ -58,7 +58,7 @@ builtin_iseq_load(const char *feature_name, const struct rb_builtin_function *ta
         .debug_level = 0,
     };
 
-    if (*rb_ruby_prism_ptr()) {
+    if (rb_ruby_prism_p()) {
         pm_parse_result_t result = { 0 };
         pm_prelude_load(&result, name_str, code, start_line);
 
diff --git a/prism_compile.h b/prism_compile.h
index 28f32cfbe9..4015091fc1 100644
--- a/prism_compile.h
+++ b/prism_compile.h
@@ -65,7 +65,6 @@ typedef struct pm_scope_node {
 
 void pm_scope_node_init(const pm_node_t *node, pm_scope_node_t *scope, pm_scope_node_t *previous);
 void pm_scope_node_destroy(pm_scope_node_t *scope_node);
-bool *rb_ruby_prism_ptr(void);
 
 typedef struct {
     /** The parser that will do the actual parsing. */
diff --git a/ruby.c b/ruby.c
index b3ddf5d3b0..accf53eec2 100644
--- a/ruby.c
+++ b/ruby.c
@@ -1430,10 +1430,10 @@ proc_long_options(ruby_cmdline_options_t *opt, const char *s, long argc, char **
     }
     else if (is_option_with_arg("parser", Qfalse, Qtrue)) {
         if (strcmp("prism", s) == 0) {
-            *rb_ruby_prism_ptr() = true;
+            rb_ruby_default_parser_set(RB_DEFAULT_PARSER_PRISM);
         }
         else if (strcmp("parse.y", s) == 0) {
-            *rb_ruby_prism_ptr() = false;
+            rb_ruby_default_parser_set(RB_DEFAULT_PARSER_PARSE_Y);
         }
         else {
             rb_raise(rb_eRuntimeError, "unknown parser %s", s);
@@ -2522,7 +2522,7 @@ process_options(int argc, char **argv, ruby_cmdline_options_t *opt)
         rb_enc_associate(opt->e_script, eenc);
     }
 
-    if (!(*rb_ruby_prism_ptr())) {
+    if (!rb_ruby_prism_p()) {
         ast_value = process_script(opt);
         if (!(result.ast = rb_ruby_ast_data_get(ast_value))) return Qfalse;
     }
diff --git a/version.c b/version.c
index 86415b83d1..3bf3ff1db4 100644
--- a/version.c
+++ b/version.c
@@ -10,6 +10,7 @@
 **********************************************************************/
 
 #include "internal/cmdlineopt.h"
+#include "internal/parse.h"
 #include "ruby/ruby.h"
 #include "version.h"
 #include "vm_core.h"
@@ -141,7 +142,22 @@ Init_version(void)
 
 int ruby_mn_threads_enabled;
 
-bool * rb_ruby_prism_ptr(void);
+#ifndef RB_DEFAULT_PARSER
+#define RB_DEFAULT_PARSER RB_DEFAULT_PARSER_PRISM
+#endif
+static ruby_default_parser_enum default_parser = RB_DEFAULT_PARSER;
+
+ruby_default_parser_enum
+rb_ruby_default_parser(void)
+{
+    return default_parser;
+}
+
+void
+rb_ruby_default_parser_set(ruby_default_parser_enum parser)
+{
+    default_parser = parser;
+}
 
 static void
 define_ruby_description(const char *const jit_opt)
@@ -158,7 +174,7 @@ define_ruby_description(const char *const jit_opt)
 # define append(s) (n += (int)strlcpy(desc + n, s, sizeof(desc) - n), assert(n < sizeof(desc)))
     if (*jit_opt) append(jit_opt);
     if (ruby_mn_threads_enabled) append(" +MN");
-    if (*rb_ruby_prism_ptr()) append(" +PRISM");
+    if (rb_ruby_prism_p()) append(" +PRISM");
     append(ruby_description + ruby_description_opt_point);
 # undef append
 
diff --git a/vm.c b/vm.c
index 6b75a7ad5a..4a31d79df7 100644
--- a/vm.c
+++ b/vm.c
@@ -4456,14 +4456,6 @@ rb_ruby_verbose_ptr(void)
     return &cr->verbose;
 }
 
-static bool prism = (RB_DEFAULT_PARSER == 1);
-
-bool *
-rb_ruby_prism_ptr(void)
-{
-    return &prism;
-}
-
 VALUE *
 rb_ruby_debug_ptr(void)
 {
diff --git a/vm_eval.c b/vm_eval.c
index baddb88b70..ff8e2e6780 100644
--- a/vm_eval.c
+++ b/vm_eval.c
@@ -1787,7 +1787,7 @@ static const rb_iseq_t *
 eval_make_iseq(VALUE src, VALUE fname, int line,
                const struct rb_block *base_block)
 {
-    if (*rb_ruby_prism_ptr()) {
+    if (rb_ruby_prism_p()) {
         return pm_eval_make_iseq(src, fname, line, base_block);
     }
     const VALUE parser = rb_parser_new();