diff --git a/include/ravi_api.h b/include/ravi_api.h
index 1b46f2d..94c4d82 100644
--- a/include/ravi_api.h
+++ b/include/ravi_api.h
@@ -28,7 +28,14 @@
 
 #include <stdlib.h>
 
-struct Ravi_CompilerInterface {
+typedef struct Ravi_MemoryAllocatorInterface {
+	void *arena;
+	void *(*realloc)(void *arena, void* mem, size_t newsize);
+	void *(*calloc)(void *arena,  size_t n_elements, size_t elem_size);
+	void (*free)(void *arena, void *p);
+} Ravi_MemoryAllocatorInterface;
+
+typedef struct Ravi_CompilerInterface {
 	/* ------------------------ Inputs ------------------------------ */
 	void *context; /* Ravi supplied context */
 
@@ -39,13 +46,15 @@ struct Ravi_CompilerInterface {
 
 	char main_func_name[31]; /* Name of the generated function that when called will set up the Lua closure */
 
+	Ravi_MemoryAllocatorInterface *memory_allocator;
+
 	/* ------------------------- Outputs ------------------------------ */
 	const char* generated_code;  /* Output of the compiler, must be freed by caller. */
 
 	/* ------------------------ Debugging and error handling ----------------------------------------- */
 	void (*debug_message)(void *context, const char *filename, long long line, const char *message);
 	void (*error_message)(void *context, const char *message);
-};
+} Ravi_CompilerInterface;
 
 /**
  * This is the API exposed by the Compiler itself. This function is invoked by
@@ -53,7 +62,7 @@ struct Ravi_CompilerInterface {
  * @param compiler_interface The interface expected by the compiler must be setup
  * @return 0 for success, non-zero for failure
  */
-RAVICOMP_EXPORT int raviX_compile(struct Ravi_CompilerInterface *compiler_interface);
-RAVICOMP_EXPORT void raviX_release(struct Ravi_CompilerInterface *compiler_interface);
+RAVICOMP_EXPORT int raviX_compile(Ravi_CompilerInterface *compiler_interface);
+RAVICOMP_EXPORT void raviX_release(Ravi_CompilerInterface *compiler_interface);
 
 #endif
diff --git a/src/chibicc/chibicc.h b/src/chibicc/chibicc.h
index ef674c9..178caf2 100644
--- a/src/chibicc/chibicc.h
+++ b/src/chibicc/chibicc.h
@@ -64,6 +64,15 @@ typedef struct C_Member C_Member;
 typedef struct C_Relocation C_Relocation;
 typedef struct C_Hideset C_Hideset;
 typedef struct C_Parser C_Parser;
+typedef struct C_MemoryAllocator C_MemoryAllocator;
+
+struct C_MemoryAllocator {
+  void *arena;
+  void *(*realloc)(void *arena, void* mem, size_t newsize);
+  void *(*calloc)(void *arena,  size_t n_elements, size_t elem_size);
+  void (*free)(void *arena, void *p);
+};
+
 
 //
 // strings.c
@@ -75,7 +84,7 @@ typedef struct {
   int len;
 } StringArray;
 
-void strarray_push(mspace arena, StringArray *arr, char *s);
+void strarray_push(C_MemoryAllocator *allocator, StringArray *arr, char *s);
 char *format(char *fmt, ...) __attribute__((format(printf, 1, 2)));
 
 //
@@ -322,7 +331,7 @@ typedef struct {
   HashEntry *buckets;
   int capacity;
   int used;
-  mspace arena;
+  C_MemoryAllocator *allocator;
 } HashMap;
 
 // Represents a block scope.
@@ -387,7 +396,7 @@ struct C_Parser {
 
   HashMap keywords; // used by tokenizer
   HashMap typewords; // used by parser
-  mspace arena; // pointer to memory arena handle
+  C_MemoryAllocator *memory_allocator;
 
   jmp_buf env;		 /* For error handling */
 
@@ -399,7 +408,7 @@ struct C_Parser {
 
 };
 
-void C_parser_init(C_Parser *parser);
+void C_parser_init(C_Parser *parser, C_MemoryAllocator *memory_allocator);
 C_Scope *C_global_scope(C_Parser *parser);
 C_Node *C_new_cast(C_Parser *parser, C_Node *expr, C_Type *ty);
 int64_t C_const_expr(C_Parser *parser, C_Token **rest, C_Token *tok);
diff --git a/src/chibicc/chibicc_hashmap.c b/src/chibicc/chibicc_hashmap.c
index 84f7914..8d76587 100644
--- a/src/chibicc/chibicc_hashmap.c
+++ b/src/chibicc/chibicc_hashmap.c
@@ -65,8 +65,8 @@ static void rehash(HashMap *map) {
 
   // Create a new hashmap and copy all key-values.
   HashMap map2 = {0};
-  map2.arena = map->arena;
-  map2.buckets = mspace_calloc(map->arena, cap, sizeof(HashEntry));
+  map2.allocator = map->allocator;
+  map2.buckets = map->allocator->calloc(map->allocator->arena, cap, sizeof(HashEntry));
   map2.capacity = cap;
 
   for (int i = 0; i < map->capacity; i++) {
@@ -76,7 +76,7 @@ static void rehash(HashMap *map) {
   }
 
   assert(map2.used == nkeys);
-  mspace_free(map->arena, map->buckets);
+  map->allocator->free(map->allocator->arena, map->buckets);
   *map = map2;
 }
 
@@ -105,8 +105,8 @@ static HashEntry *get_entry(HashMap *map, char *key, int keylen) {
 
 static HashEntry *get_or_insert_entry(HashMap *map, char *key, int keylen) {
   if (!map->buckets) {
-    assert(map->arena != NULL);
-    map->buckets = mspace_calloc(map->arena, INIT_SIZE, sizeof(HashEntry));
+    assert(map->allocator != NULL);
+    map->buckets = map->allocator->calloc(map->allocator->arena, INIT_SIZE, sizeof(HashEntry));
     map->capacity = INIT_SIZE;
   } else if ((map->used * 100) / map->capacity >= HIGH_WATERMARK) {
     rehash(map);
diff --git a/src/chibicc/chibicc_parse.c b/src/chibicc/chibicc_parse.c
index 530b05e..2e2d045 100644
--- a/src/chibicc/chibicc_parse.c
+++ b/src/chibicc/chibicc_parse.c
@@ -142,24 +142,24 @@ static int align_down(int n, int align) {
   return C_align_to(n - align + 1, align);
 }
 
-static char *str_dup(mspace arena, const char *temp, size_t len) {
-  char *p = (char *) mspace_calloc(arena, 1, len+1);
+static char *str_dup(struct C_MemoryAllocator *allocator, const char *temp, size_t len) {
+  char *p = (char *) allocator->calloc(allocator->arena, 1, len+1);
   memcpy(p, temp, len);
   p[len] = 0;
   return p;
 }
 
 C_Scope *C_global_scope(C_Parser *parser) {
-  C_Scope *sc = mspace_calloc(parser->arena, 1, sizeof(C_Scope));
-  sc->vars.arena = parser->arena;
-  sc->tags.arena = parser->arena;
+  C_Scope *sc = parser->memory_allocator->calloc(parser->memory_allocator->arena, 1, sizeof(C_Scope));
+  sc->vars.allocator = parser->memory_allocator;
+  sc->tags.allocator = parser->memory_allocator;
   return sc;
 }
 
 static void enter_scope(C_Parser *parser) {
-  C_Scope *sc = mspace_calloc(parser->arena, 1, sizeof(C_Scope));
-  sc->vars.arena = parser->arena;
-  sc->tags.arena = parser->arena;
+  C_Scope *sc = parser->memory_allocator->calloc(parser->memory_allocator->arena, 1, sizeof(C_Scope));
+  sc->vars.allocator = parser->memory_allocator;
+  sc->tags.allocator = parser->memory_allocator;
   sc->next = parser->scope;
   parser->scope = sc;
 }
@@ -188,7 +188,7 @@ static C_Type *find_tag(C_Parser *parser, C_Token *tok) {
 }
 
 static C_Node *new_node(C_Parser *parser, C_NodeKind kind, C_Token *tok) {
-  C_Node *node = mspace_calloc(parser->arena,1, sizeof(C_Node));
+  C_Node *node = parser->memory_allocator->calloc(parser->memory_allocator->arena,1, sizeof(C_Node));
   node->kind = kind;
   node->tok = tok;
   return node;
@@ -242,7 +242,7 @@ static C_Node *new_vla_ptr(C_Parser *parser, C_Obj *var, C_Token *tok) {
 C_Node *C_new_cast(C_Parser *parser, C_Node *expr, C_Type *ty) {
   C_add_type(parser, expr);
 
-  C_Node *node = mspace_calloc( parser->arena,1, sizeof(C_Node));
+  C_Node *node = parser->memory_allocator->calloc(parser->memory_allocator->arena,1, sizeof(C_Node));
   node->kind = ND_CAST;
   node->tok = expr->tok;
   node->lhs = expr;
@@ -251,13 +251,13 @@ C_Node *C_new_cast(C_Parser *parser, C_Node *expr, C_Type *ty) {
 }
 
 static C_VarScope *push_scope(C_Parser *parser, char *name) {
-  C_VarScope *sc = mspace_calloc(parser->arena,1, sizeof(C_VarScope));
+  C_VarScope *sc = parser->memory_allocator->calloc(parser->memory_allocator->arena,1, sizeof(C_VarScope));
   hashmap_put(&parser->scope->vars, name, sc);
   return sc;
 }
 
 static Initializer *new_initializer(C_Parser *parser, C_Type *ty, bool is_flexible) {
-  Initializer *init = mspace_calloc(parser->arena,1, sizeof(Initializer));
+  Initializer *init = parser->memory_allocator->calloc(parser->memory_allocator->arena,1, sizeof(Initializer));
   init->ty = ty;
 
   if (ty->kind == TY_ARRAY) {
@@ -266,7 +266,7 @@ static Initializer *new_initializer(C_Parser *parser, C_Type *ty, bool is_flexib
       return init;
     }
 
-    init->children = mspace_calloc(parser->arena, ty->array_len, sizeof(Initializer *));
+    init->children = parser->memory_allocator->calloc(parser->memory_allocator->arena, ty->array_len, sizeof(Initializer *));
     for (int i = 0; i < ty->array_len; i++)
       init->children[i] = new_initializer(parser, ty->base, false);
     return init;
@@ -278,11 +278,11 @@ static Initializer *new_initializer(C_Parser *parser, C_Type *ty, bool is_flexib
     for (C_Member *mem = ty->members; mem; mem = mem->next)
       len++;
 
-    init->children = mspace_calloc(parser->arena, len, sizeof(Initializer *));
+    init->children = parser->memory_allocator->calloc(parser->memory_allocator->arena, len, sizeof(Initializer *));
 
     for (C_Member *mem = ty->members; mem; mem = mem->next) {
       if (is_flexible && ty->is_flexible && !mem->next) {
-        Initializer *child = mspace_calloc(parser->arena, 1, sizeof(Initializer));
+        Initializer *child = parser->memory_allocator->calloc(parser->memory_allocator->arena, 1, sizeof(Initializer));
         child->ty = mem->ty;
         child->is_flexible = true;
         init->children[mem->idx] = child;
@@ -297,7 +297,7 @@ static Initializer *new_initializer(C_Parser *parser, C_Type *ty, bool is_flexib
 }
 
 static C_Obj *new_var(C_Parser *parser, char *name, C_Type *ty) {
-  C_Obj *var = mspace_calloc(parser->arena, 1, sizeof(C_Obj));
+  C_Obj *var = parser->memory_allocator->calloc(parser->memory_allocator->arena, 1, sizeof(C_Obj));
   var->name = name;
   var->ty = ty;
   var->align = ty->align;
@@ -331,7 +331,7 @@ static char *new_unique_name(mspace arena) {
 }
 
 static C_Obj *new_anon_gvar(C_Parser *parser, C_Type *ty) {
-  return new_gvar(parser, new_unique_name(parser->arena), ty);
+  return new_gvar(parser, new_unique_name(parser->memory_allocator), ty);
 }
 
 static C_Obj *new_string_literal(C_Parser *parser, char *p, C_Type *ty) {
@@ -343,7 +343,7 @@ static C_Obj *new_string_literal(C_Parser *parser, char *p, C_Type *ty) {
 static char *get_ident(C_Parser *parser, C_Token *tok) {
   if (tok->kind != TK_IDENT)
     C_error_tok(parser, tok, "expected an identifier");
-  return str_dup(parser->arena, tok->loc, tok->len);
+  return str_dup(parser->memory_allocator, tok->loc, tok->len);
 }
 
 static C_Type *find_typedef(C_Parser *parser, C_Token *tok) {
@@ -1283,7 +1283,7 @@ static C_Type *copy_struct_type(C_Parser *parser, C_Type *ty) {
   C_Member head = {0};
   C_Member *cur = &head;
   for (C_Member *mem = ty->members; mem; mem = mem->next) {
-    C_Member *m = mspace_calloc(parser->arena, 1, sizeof(C_Member));
+    C_Member *m = parser->memory_allocator->calloc(parser->memory_allocator->arena, 1, sizeof(C_Member));
     *m = *mem;
     cur = cur->next = m;
   }
@@ -1471,7 +1471,7 @@ write_gvar_data(C_Parser *parser, C_Relocation *cur, Initializer *init, C_Type *
     return cur;
   }
 
-  C_Relocation *rel = mspace_calloc(parser->arena, 1, sizeof(C_Relocation));
+  C_Relocation *rel = parser->memory_allocator->calloc(parser->memory_allocator->arena, 1, sizeof(C_Relocation));
   rel->offset = offset;
   rel->label = label;
   rel->addend = val;
@@ -1487,7 +1487,7 @@ static void gvar_initializer(C_Parser *parser, C_Token **rest, C_Token *tok, C_O
   Initializer *init = initializer(parser, rest, tok, var->ty, &var->ty);
 
   C_Relocation head = {0};
-  char *buf = mspace_calloc(parser->arena, 1, var->ty->size);
+  char *buf = parser->memory_allocator->calloc(parser->memory_allocator->arena, 1, var->ty->size);
   write_gvar_data(parser, &head, init, var->ty, buf, 0);
   var->init_data = buf;
   var->rel = head.next;
@@ -1581,7 +1581,7 @@ static C_Node *stmt(C_Parser *parser, C_Token **rest, C_Token *tok) {
     parser->current_switch = node;
 
     char *brk = parser->brk_label;
-    parser->brk_label = node->brk_label = new_unique_name(parser->arena);
+    parser->brk_label = node->brk_label = new_unique_name(parser->memory_allocator);
 
     node->then = stmt(parser, rest, tok);
 
@@ -1608,7 +1608,7 @@ static C_Node *stmt(C_Parser *parser, C_Token **rest, C_Token *tok) {
     }
 
     tok = C_skip(parser, tok, ":");
-    node->label = new_unique_name(parser->arena);
+    node->label = new_unique_name(parser->memory_allocator);
     node->lhs = stmt(parser, rest, tok);
     node->begin = begin;
     node->end = end;
@@ -1623,7 +1623,7 @@ static C_Node *stmt(C_Parser *parser, C_Token **rest, C_Token *tok) {
 
     C_Node *node = new_node(parser, ND_CASE, tok);
     tok = C_skip(parser, tok->next, ":");
-    node->label = new_unique_name(parser->arena);
+    node->label = new_unique_name(parser->memory_allocator);
     node->lhs = stmt(parser, rest, tok);
     parser->current_switch->default_case = node;
     return node;
@@ -1637,8 +1637,8 @@ static C_Node *stmt(C_Parser *parser, C_Token **rest, C_Token *tok) {
 
     char *brk = parser->brk_label;
     char *cont = parser->cont_label;
-    parser->brk_label = node->brk_label = new_unique_name(parser->arena);
-    parser->cont_label = node->cont_label = new_unique_name(parser->arena);
+    parser->brk_label = node->brk_label = new_unique_name(parser->memory_allocator);
+    parser->cont_label = node->cont_label = new_unique_name(parser->memory_allocator);
 
     if (is_typename(parser, tok)) {
       C_Type *basety = declspec(parser, &tok, tok, NULL);
@@ -1671,8 +1671,8 @@ static C_Node *stmt(C_Parser *parser, C_Token **rest, C_Token *tok) {
 
     char *brk = parser->brk_label;
     char *cont = parser->cont_label;
-    parser->brk_label = node->brk_label = new_unique_name(parser->arena);
-    parser->cont_label = node->cont_label = new_unique_name(parser->arena);
+    parser->brk_label = node->brk_label = new_unique_name(parser->memory_allocator);
+    parser->cont_label = node->cont_label = new_unique_name(parser->memory_allocator);
 
     node->then = stmt(parser, rest, tok);
 
@@ -1686,8 +1686,8 @@ static C_Node *stmt(C_Parser *parser, C_Token **rest, C_Token *tok) {
 
     char *brk = parser->brk_label;
     char *cont = parser->cont_label;
-    parser->brk_label = node->brk_label = new_unique_name(parser->arena);
-    parser->cont_label = node->cont_label = new_unique_name(parser->arena);
+    parser->brk_label = node->brk_label = new_unique_name(parser->memory_allocator);
+    parser->cont_label = node->cont_label = new_unique_name(parser->memory_allocator);
 
     node->then = stmt(parser, &tok, tok->next);
 
@@ -1742,8 +1742,8 @@ static C_Node *stmt(C_Parser *parser, C_Token **rest, C_Token *tok) {
 
   if (tok->kind == TK_IDENT && C_equal(tok->next, ":")) {
     C_Node *node = new_node(parser, ND_LABEL, tok);
-    node->label = str_dup(parser->arena, tok->loc, tok->len);
-    node->unique_label = new_unique_name(parser->arena);
+    node->label = str_dup(parser->memory_allocator, tok->loc, tok->len);
+    node->unique_label = new_unique_name(parser->memory_allocator);
     node->lhs = stmt(parser, rest, tok->next->next);
     node->goto_next = parser->labels;
     parser->labels = node;
@@ -2092,8 +2092,8 @@ static C_Node *to_assign(C_Parser *parser, C_Node *binary) {
                 tok);
 
     C_Node *loop = new_node(parser, ND_DO, tok);
-    loop->brk_label = new_unique_name(parser->arena);
-    loop->cont_label = new_unique_name(parser->arena);
+    loop->brk_label = new_unique_name(parser->memory_allocator);
+    loop->cont_label = new_unique_name(parser->memory_allocator);
 
     C_Node *body = new_binary(parser, ND_ASSIGN,
                             new_var_node(parser, new, tok),
@@ -2552,7 +2552,7 @@ static void struct_members(C_Parser *parser, C_Token **rest, C_Token *tok, C_Typ
 
     // Anonymous struct member
     if ((basety->kind == TY_STRUCT || basety->kind == TY_UNION) && C_consume(&tok, tok, ";")) {
-      C_Member *mem = mspace_calloc(parser->arena, 1, sizeof(C_Member));
+      C_Member *mem = parser->memory_allocator->calloc(parser->memory_allocator->arena, 1, sizeof(C_Member));
       mem->ty = basety;
       mem->idx = idx++;
       mem->align = attr.align ? attr.align : mem->ty->align;
@@ -2566,7 +2566,7 @@ static void struct_members(C_Parser *parser, C_Token **rest, C_Token *tok, C_Typ
         tok = C_skip(parser, tok, ",");
       first = false;
 
-      C_Member *mem = mspace_calloc(parser->arena, 1, sizeof(C_Member));
+      C_Member *mem = parser->memory_allocator->calloc(parser->memory_allocator->arena, 1, sizeof(C_Member));
       mem->ty = declarator(parser, &tok, tok, basety);
       mem->name = mem->ty->name;
       mem->idx = idx++;
@@ -3087,7 +3087,7 @@ static C_Node *primary(C_Parser *parser, C_Token **rest, C_Token *tok) {
     // For "static inline" function
     if (sc && sc->var && sc->var->is_function) {
       if (parser->current_fn)
-        strarray_push(parser->arena, &parser->current_fn->refs, sc->var->name);
+        strarray_push(parser->memory_allocator, &parser->current_fn->refs, sc->var->name);
       else
         sc->var->is_root = true;
     }
@@ -3399,15 +3399,13 @@ C_Obj *C_parse(C_Scope *globalScope, C_Parser *parser, C_Token *tok) {
   return parser->globals;
 }
 
-void C_parser_init(C_Parser *parser) {
+void C_parser_init(C_Parser *parser, C_MemoryAllocator *allocator) {
   memset(parser, 0, sizeof *parser);
-  parser->arena = create_mspace(0, 0);
-  parser->keywords.arena = parser->arena;
-  parser->typewords.arena = parser->arena;
+  parser->memory_allocator = allocator;
+  parser->keywords.allocator = allocator;
+  parser->typewords.allocator = allocator;
 }
 
 void C_parser_destroy(C_Parser *parser) {
-  //mspace_malloc_stats(parser->arena);
-  destroy_mspace(parser->arena);
-  parser->arena = NULL;
+  parser->memory_allocator = NULL;
 }
\ No newline at end of file
diff --git a/src/chibicc/chibicc_strings.c b/src/chibicc/chibicc_strings.c
index a780538..fc166f1 100644
--- a/src/chibicc/chibicc_strings.c
+++ b/src/chibicc/chibicc_strings.c
@@ -27,14 +27,14 @@ SOFTWARE.
 
 #include "chibicc.h"
 
-void strarray_push(mspace arena, StringArray *arr, char *s) {
+void strarray_push(C_MemoryAllocator *allocator, StringArray *arr, char *s) {
   if (!arr->data) {
-    arr->data = mspace_calloc(arena, 8, sizeof(char *));
+    arr->data = allocator->calloc(allocator->arena, 8, sizeof(char *));
     arr->capacity = 8;
   }
 
   if (arr->capacity == arr->len) {
-    arr->data = mspace_realloc(arena, arr->data, sizeof(char *) * arr->capacity * 2);
+    arr->data = allocator->realloc(allocator->arena, arr->data, sizeof(char *) * arr->capacity * 2);
     arr->capacity *= 2;
     for (int i = arr->len; i < arr->capacity; i++)
       arr->data[i] = NULL;
diff --git a/src/chibicc/chibicc_tokenize.c b/src/chibicc/chibicc_tokenize.c
index 2248258..e5a0089 100644
--- a/src/chibicc/chibicc_tokenize.c
+++ b/src/chibicc/chibicc_tokenize.c
@@ -33,7 +33,7 @@ static int error_sprintf(C_Parser *parser, const char *fmt, ...) {
   int estimated_size = 128;
   int n = 0;
   for (int i = 0; i < 2; i++) {
-    parser->error_message = mspace_realloc(parser->arena, parser->error_message, pos + estimated_size); // ensure we have at least estimated_size free space
+    parser->error_message = parser->memory_allocator->realloc(parser->memory_allocator->arena, parser->error_message, pos + estimated_size); // ensure we have at least estimated_size free space
     va_start(args, fmt);
     n = vsnprintf(parser->error_message + pos, estimated_size, fmt, args);
     va_end(args);
@@ -55,7 +55,7 @@ static int error_vsprintf(C_Parser *parser, const char *fmt, va_list args) {
   int pos = parser->error_message ? (int)strlen(parser->error_message) : 0;
   int n = 0;
   for (int i = 0; i < 2; i++) {
-    parser->error_message = mspace_realloc(parser->arena, parser->error_message, pos + estimated_size); // ensure we have at least estimated_size free space
+    parser->error_message = parser->memory_allocator->realloc(parser->memory_allocator->arena, parser->error_message, pos + estimated_size); // ensure we have at least estimated_size free space
     n = vsnprintf(parser->error_message + pos, estimated_size, fmt, args);
     if (n >= estimated_size) {
       estimated_size = n + 1; // allow for 0 byte
@@ -157,7 +157,7 @@ bool C_consume(C_Token **rest, C_Token *tok, char *str) {
 
 // Create a new token.
 static C_Token *new_token(C_Parser *tokenizer, C_TokenKind kind, char *start, char *end) {
-  C_Token *tok = mspace_calloc(tokenizer->arena, 1, sizeof(C_Token));
+  C_Token *tok = tokenizer->memory_allocator->calloc(tokenizer->memory_allocator->arena, 1, sizeof(C_Token));
   tok->kind = kind;
   tok->loc = start;
   tok->len = end - start;
@@ -301,7 +301,7 @@ static char *string_literal_end(C_Parser *tokenizer, char *p) {
 
 static C_Token *read_string_literal(C_Parser *tokenizer, char *start, char *quote) {
   char *end = string_literal_end(tokenizer,quote + 1);
-  char *buf = mspace_calloc(tokenizer->arena, 1, end - quote);
+  char *buf = tokenizer->memory_allocator->calloc(tokenizer->memory_allocator->arena, 1, end - quote);
   int len = 0;
 
   for (char *p = quote + 1; p < end;) {
@@ -326,7 +326,7 @@ static C_Token *read_string_literal(C_Parser *tokenizer, char *start, char *quot
 // is called a "surrogate pair".
 static C_Token *read_utf16_string_literal(C_Parser *tokenizer, char *start, char *quote) {
   char *end = string_literal_end(tokenizer, quote + 1);
-  uint16_t *buf = mspace_calloc(tokenizer->arena, 2, end - start);
+  uint16_t *buf = tokenizer->memory_allocator->calloc(tokenizer->memory_allocator->arena, 2, end - start);
   int len = 0;
 
   for (char *p = quote + 1; p < end;) {
@@ -359,7 +359,7 @@ static C_Token *read_utf16_string_literal(C_Parser *tokenizer, char *start, char
 // encoded in 4 bytes.
 static C_Token *read_utf32_string_literal(C_Parser *tokenizer, char *start, char *quote, C_Type *ty) {
   char *end = string_literal_end(tokenizer, quote + 1);
-  uint32_t *buf = mspace_calloc(tokenizer->arena, 4, end - quote);
+  uint32_t *buf = tokenizer->memory_allocator->calloc(tokenizer->memory_allocator->arena, 4, end - quote);
   int len = 0;
 
   for (char *p = quote + 1; p < end;) {
@@ -739,7 +739,7 @@ C_File **get_input_files(C_Parser *tokenizer) {
 
 
 C_File *C_new_file(C_Parser *tokenizer, char *name, int file_no, char *contents) {
-  C_File *file = mspace_calloc(tokenizer->arena, 1, sizeof(C_File));
+  C_File *file = tokenizer->memory_allocator->calloc(tokenizer->memory_allocator->arena, 1, sizeof(C_File));
   file->name = name;
   file->display_name = name;
   file->file_no = file_no;
@@ -868,7 +868,7 @@ C_Token *C_tokenize_buffer(C_Parser *tokenizer, char *p) {
   C_File *file = C_new_file(tokenizer, "", file_no + 1, p);
 
   // Save the filename for assembler .file directive.
-  tokenizer->input_files = mspace_realloc(tokenizer->arena, tokenizer->input_files, sizeof(char *) * (file_no + 2));
+  tokenizer->input_files = tokenizer->memory_allocator->realloc(tokenizer->memory_allocator->arena, tokenizer->input_files, sizeof(char *) * (file_no + 2));
   tokenizer->input_files[file_no] = file;
   tokenizer->input_files[file_no + 1] = NULL;
   file_no++;
diff --git a/src/chibicc/chibicc_type.c b/src/chibicc/chibicc_type.c
index f79616c..e4594fe 100644
--- a/src/chibicc/chibicc_type.c
+++ b/src/chibicc/chibicc_type.c
@@ -44,7 +44,7 @@ C_Type *C_ty_double = &(C_Type){TY_DOUBLE, 8, 8};
 C_Type *C_ty_ldouble = &(C_Type){TY_LDOUBLE, 16, 16};
 
 static C_Type *new_type(C_Parser *parser, TypeKind kind, int size, int align) {
-  C_Type *ty = mspace_calloc(parser->arena, 1, sizeof(C_Type));
+  C_Type *ty = parser->memory_allocator->calloc(parser->memory_allocator->arena, 1, sizeof(C_Type));
   ty->kind = kind;
   ty->size = size;
   ty->align = align;
@@ -114,7 +114,7 @@ bool C_is_compatible(C_Type *t1, C_Type *t2) {
 }
 
 C_Type *C_copy_type(C_Parser *parser, C_Type *ty) {
-  C_Type *ret = mspace_calloc(parser->arena, 1, sizeof(C_Type));
+  C_Type *ret = parser->memory_allocator->calloc(parser->memory_allocator->arena, 1, sizeof(C_Type));
   *ret = *ty;
   ret->origin = ty;
   return ret;
diff --git a/src/codegen.c b/src/codegen.c
index 3ed3a00..e22088e 100644
--- a/src/codegen.c
+++ b/src/codegen.c
@@ -2764,9 +2764,16 @@ static int analyze_C_code(Function *fn, TextBuffer *user_code)
 	if (fn->C_local_declarations.buf) /* declarations of temp integer and float vars */
 		raviX_buffer_add_string(&canned_code, fn->C_local_declarations.buf);
 
+	C_MemoryAllocator allocator;
+	allocator.arena = create_mspace(0, 0);
+	allocator.realloc = mspace_realloc;
+	allocator.calloc = mspace_calloc;
+	allocator.free = mspace_free;
+
 	C_Code_Analysis analysis = {0};
 	C_Parser parser;
-	C_parser_init(&parser);
+
+	C_parser_init(&parser, &allocator);
 	C_Scope *global_scope = C_global_scope(&parser);
 	C_Token *tok = C_tokenize_buffer(&parser, canned_code.buf);
 	if (tok == NULL) {
@@ -2801,6 +2808,7 @@ static int analyze_C_code(Function *fn, TextBuffer *user_code)
 		fn->api->error_message(fn->api->context, parser.error_message);
 	}
 	C_parser_destroy(&parser);
+	destroy_mspace(allocator.arena);
 	raviX_buffer_free(&canned_code);
 
 	return analysis.status;
@@ -2969,8 +2977,15 @@ static int emit_op_C__new(Function *fn, Instruction *insn)
 	raviX_buffer_add_string(&code, linearizer->C_declarations.buf);
 
 	int status = -1;
+
+	C_MemoryAllocator allocator;
+	allocator.arena = create_mspace(0, 0);
+	allocator.realloc = mspace_realloc;
+	allocator.calloc = mspace_calloc;
+	allocator.free = mspace_free;
+
 	C_Parser parser;
-	C_parser_init(&parser);
+	C_parser_init(&parser, &allocator);
 	C_Scope *global_scope = C_global_scope(&parser);
 	C_Token *tok = C_tokenize_buffer(&parser, code.buf);
 	if (tok == NULL) {
@@ -3025,6 +3040,7 @@ static int emit_op_C__new(Function *fn, Instruction *insn)
 
 Lexit:
 	C_parser_destroy(&parser);
+	destroy_mspace(allocator.arena);
 	raviX_buffer_free(&code);
 
 	return status;
@@ -3534,8 +3550,14 @@ static int emit_C__decl(LinearizerState *linearizer, struct Ravi_CompilerInterfa
 	raviX_buffer_add_string(&code, Embedded_C_header);
 	raviX_buffer_add_string(&code, linearizer->C_declarations.buf);
 
+	C_MemoryAllocator allocator;
+	allocator.arena = create_mspace(0, 0);
+	allocator.realloc = mspace_realloc;
+	allocator.calloc = mspace_calloc;
+	allocator.free = mspace_free;
+
 	C_Parser parser;
-	C_parser_init(&parser);
+	C_parser_init(&parser, &allocator);
 	C_Scope *global_scope = C_global_scope(&parser);
 	C_Decl_Analysis analysis = {&parser, global_scope, 0, 0, api};
 
@@ -3566,6 +3588,7 @@ static int emit_C__decl(LinearizerState *linearizer, struct Ravi_CompilerInterfa
 		api->error_message(api->context, parser.error_message);
 	}
 	C_parser_destroy(&parser);
+	destroy_mspace(allocator.arena);
 	raviX_buffer_free(&code);
 
 	return analysis.status;
diff --git a/tests/tchibicc.c b/tests/tchibicc.c
index 0284745..5cbf096 100644
--- a/tests/tchibicc.c
+++ b/tests/tchibicc.c
@@ -17,13 +17,18 @@ int main(int argc, const char *argv[])
 	" int len;\n" \
 	"} Str;\n";
 	strncpy(buffer, code, sizeof buffer);
+	C_MemoryAllocator allocator;
+	allocator.arena = create_mspace(0, 0);
+	allocator.free = mspace_free;
+	allocator.calloc = mspace_calloc;
+	allocator.realloc = mspace_realloc;
 	C_Parser parser = {0};
-	C_parser_init(&parser);
+	C_parser_init(&parser, &allocator);
 	C_Token *tok = C_tokenize_buffer(&parser, buffer);
 	C_convert_pp_tokens(&parser, tok);
 	C_Scope scope = {0};
-	scope.vars.arena = parser.arena;
-	scope.tags.arena = parser.arena;
+	scope.vars.allocator = parser.memory_allocator;
+	scope.tags.allocator = parser.memory_allocator;
 	C_Obj *obj = C_parse(&scope, &parser, tok);
 	hashmap_foreach(&scope.vars, printout, NULL);
 	C_create_function(&scope, &parser, "dummy");