diff --git a/include/pocketpy/config.h b/include/pocketpy/config.h
index a5577af7..29c3257d 100644
--- a/include/pocketpy/config.h
+++ b/include/pocketpy/config.h
@@ -18,6 +18,13 @@
 #define PK_GC_MIN_THRESHOLD         16384
 #endif
 
+// Memory allocation functions
+#ifndef PK_MALLOC
+#define PK_MALLOC(size)             malloc(size)
+#define PK_REALLOC(ptr, size)       realloc(ptr, size)
+#define PK_FREE(ptr)                free(ptr)
+#endif
+
 /*************** debug settings ***************/
 // Do not edit the following settings unless you know what you are doing
 #define PK_DEBUG_CEVAL_STEP         0
diff --git a/include/pocketpy/xmacros/smallmap.h b/include/pocketpy/xmacros/smallmap.h
index 10bfee54..dfb95c29 100644
--- a/include/pocketpy/xmacros/smallmap.h
+++ b/include/pocketpy/xmacros/smallmap.h
@@ -59,7 +59,7 @@ void METHOD(ctor)(NAME* self) {
 void METHOD(dtor)(NAME* self) { c11_vector__dtor(self); }
 
 NAME* METHOD(new)() {
-    NAME* self = malloc(sizeof(NAME));
+    NAME* self = PK_MALLOC(sizeof(NAME));
     METHOD(ctor)(self);
     return self;
 }
diff --git a/src/common/algorithm.c b/src/common/algorithm.c
index e908984e..025dfa4d 100644
--- a/src/common/algorithm.c
+++ b/src/common/algorithm.c
@@ -1,4 +1,5 @@
 #include "pocketpy/common/algorithm.h"
+#include "pocketpy/config.h"
 #include <string.h>
 #include <stdlib.h>
 
@@ -38,7 +39,7 @@ bool c11__stable_sort(void* ptr_,
                       int (*f_lt)(const void* a, const void* b, void* extra),
                       void* extra) {
     // merge sort
-    char *ptr = ptr_, *tmp = malloc(length * elem_size);
+    char *ptr = ptr_, *tmp = PK_MALLOC(length * elem_size);
     for(int seg = 1; seg < length; seg *= 2) {
         for(char* a = ptr; a < ptr + (length - seg) * elem_size; a += 2 * seg * elem_size) {
             char *b = a + seg * elem_size, *a_end = b, *b_end = b + seg * elem_size;
diff --git a/src/common/memorypool.c b/src/common/memorypool.c
index 41116d59..bf1c212f 100644
--- a/src/common/memorypool.c
+++ b/src/common/memorypool.c
@@ -136,7 +136,7 @@ static void MemoryPool__ctor(MemoryPool* self) {
 static void* MemoryPool__alloc(MemoryPool* self) {
     MemoryPoolArena* arena;
     if(self->_arenas.length == 0){
-        arena = malloc(sizeof(MemoryPoolArena));
+        arena = PK_MALLOC(sizeof(MemoryPoolArena));
         MemoryPoolArena__ctor(arena);
         LinkedList__push_back(&self->_arenas, (LinkedListNode*)arena);
     } else {
@@ -195,9 +195,9 @@ static void FixedMemoryPool__ctor(FixedMemoryPool* self, int BlockSize, int Bloc
     self->BlockSize = BlockSize;
     self->BlockCount = BlockCount;
     self->exceeded_bytes = 0;
-    self->data = malloc(BlockSize * BlockCount);
+    self->data = PK_MALLOC(BlockSize * BlockCount);
     self->data_end = self->data + BlockSize * BlockCount;
-    self->_free_list = malloc(sizeof(void*) * BlockCount);
+    self->_free_list = PK_MALLOC(sizeof(void*) * BlockCount);
     self->_free_list_end = self->_free_list;
     for(int i = 0; i < BlockCount; i++) {
         self->_free_list[i] = self->data + i * BlockSize;
@@ -215,7 +215,7 @@ static void* FixedMemoryPool__alloc(FixedMemoryPool* self) {
         return *self->_free_list_end;
     } else {
         self->exceeded_bytes += self->BlockSize;
-        return malloc(self->BlockSize);
+        return PK_MALLOC(self->BlockSize);
     }
 }
 
diff --git a/src/common/sourcedata.c b/src/common/sourcedata.c
index 4ec0e921..fee47d74 100644
--- a/src/common/sourcedata.c
+++ b/src/common/sourcedata.c
@@ -39,7 +39,7 @@ SourceData_ SourceData__rcnew(const char* source,
                               const char* filename,
                               enum py_CompileMode mode,
                               bool is_dynamic) {
-    SourceData_ self = malloc(sizeof(struct SourceData));
+    SourceData_ self = PK_MALLOC(sizeof(struct SourceData));
     SourceData__ctor(self, source, filename, mode, is_dynamic);
     self->rc.count = 1;
     self->rc.dtor = (void (*)(void*))SourceData__dtor;
diff --git a/src/common/str.c b/src/common/str.c
index 3e17a74b..bc7645d4 100644
--- a/src/common/str.c
+++ b/src/common/str.c
@@ -11,7 +11,7 @@
 c11_string* c11_string__new(const char* data) { return c11_string__new2(data, strlen(data)); }
 
 c11_string* c11_string__new2(const char* data, int size) {
-    c11_string* retval = malloc(sizeof(c11_string) + size + 1);
+    c11_string* retval = PK_MALLOC(sizeof(c11_string) + size + 1);
     c11_string__ctor2(retval, data, size);
     return retval;
 }
@@ -46,7 +46,7 @@ void c11_string__ctor3(c11_string* self, int size) {
 
 c11_string* c11_string__copy(c11_string* self) {
     int total_size = sizeof(c11_string) + self->size + 1;
-    c11_string* retval = malloc(total_size);
+    c11_string* retval = PK_MALLOC(total_size);
     memcpy(retval, self, total_size);
     return retval;
 }
diff --git a/src/common/strname.c b/src/common/strname.c
index 40ca110c..b586ffbf 100644
--- a/src/common/strname.c
+++ b/src/common/strname.c
@@ -41,7 +41,7 @@ py_Name py_namev(c11_sv name) {
     // generate new index
     if(_interned.length > 65530) c11__abort("py_Name index overflow");
     // NOTE: we must allocate the string in the heap so iterators are not invalidated
-    char* p = malloc(name.size + 1);
+    char* p = PK_MALLOC(name.size + 1);
     memcpy(p, name.data, name.size);
     p[name.size] = '\0';
     c11_vector__push(char*, &_r_interned, p);
diff --git a/src/compiler/compiler.c b/src/compiler/compiler.c
index 2b3fea01..747faa82 100644
--- a/src/compiler/compiler.c
+++ b/src/compiler/compiler.c
@@ -526,7 +526,7 @@ static SequenceExpr* SequenceExpr__new(int line, const ExprVt* vt, int count, Op
     self->vt = vt;
     self->line = line;
     self->opcode = opcode;
-    self->items = malloc(sizeof(Expr*) * count);
+    self->items = PK_MALLOC(sizeof(Expr*) * count);
     self->itemCount = count;
     return self;
 }
@@ -1359,7 +1359,7 @@ static NameScope name_scope(Compiler* self) {
 }
 
 Error* SyntaxError(Compiler* self, const char* fmt, ...) {
-    Error* err = malloc(sizeof(Error));
+    Error* err = PK_MALLOC(sizeof(Error));
     err->src = self->src;
     PK_INCREF(self->src);
     Token* t = self->i == self->tokens_length ? prev() : curr();
diff --git a/src/compiler/lexer.c b/src/compiler/lexer.c
index f2bb4ea6..8d6eef4f 100644
--- a/src/compiler/lexer.c
+++ b/src/compiler/lexer.c
@@ -186,7 +186,7 @@ static bool is_possible_number_char(char c) {
 
 /******************************/
 static Error* LexerError(Lexer* self, const char* fmt, ...) {
-    Error* err = malloc(sizeof(Error));
+    Error* err = PK_MALLOC(sizeof(Error));
     err->src = self->src;
     PK_INCREF(self->src);
     err->lineno = self->current_line;
diff --git a/src/interpreter/frame.c b/src/interpreter/frame.c
index da1b54e4..07c1830b 100644
--- a/src/interpreter/frame.c
+++ b/src/interpreter/frame.c
@@ -28,7 +28,7 @@ NameDict* FastLocals__to_namedict(py_TValue* locals, const CodeObject* co) {
 }
 
 UnwindTarget* UnwindTarget__new(UnwindTarget* next, int iblock, int offset) {
-    UnwindTarget* self = malloc(sizeof(UnwindTarget));
+    UnwindTarget* self = PK_MALLOC(sizeof(UnwindTarget));
     self->next = next;
     self->iblock = iblock;
     self->offset = offset;
diff --git a/src/interpreter/heap.c b/src/interpreter/heap.c
index 54afe05a..7c0d37d6 100644
--- a/src/interpreter/heap.c
+++ b/src/interpreter/heap.c
@@ -95,7 +95,7 @@ PyObject* PyObject__new(py_Type type, int slots, int size) {
         self = PoolObject_alloc();
         self->gc_is_large = false;
     } else {
-        self = malloc(size);
+        self = PK_MALLOC(size);
         self->gc_is_large = true;
     }
     self->type = type;
diff --git a/src/interpreter/typeinfo.c b/src/interpreter/typeinfo.c
index 8e9c97dd..460de30d 100644
--- a/src/interpreter/typeinfo.c
+++ b/src/interpreter/typeinfo.c
@@ -26,7 +26,7 @@ py_TypeInfo* TypeList__emplace(TypeList* self){
     int offset = self->length & (CHUNK_SIZE - 1);
     assert(chunk < 256);
     if(self->chunks[chunk] == NULL){
-        self->chunks[chunk] = malloc(sizeof(py_TypeInfo) * CHUNK_SIZE);
+        self->chunks[chunk] = PK_MALLOC(sizeof(py_TypeInfo) * CHUNK_SIZE);
         memset(self->chunks[chunk], 0, sizeof(py_TypeInfo) * CHUNK_SIZE);
     }
     self->length++;
diff --git a/src/interpreter/vm.c b/src/interpreter/vm.c
index 7913e44d..904e49c3 100644
--- a/src/interpreter/vm.c
+++ b/src/interpreter/vm.c
@@ -17,7 +17,7 @@ static char* pk_default_importfile(const char* path) {
     fseek(f, 0, SEEK_END);
     long size = ftell(f);
     fseek(f, 0, SEEK_SET);
-    char* buffer = malloc(size + 1);
+    char* buffer = PK_MALLOC(size + 1);
     size = fread(buffer, 1, size, f);
     buffer[size] = 0;
     fclose(f);
diff --git a/src/modules/os.c b/src/modules/os.c
index c55f65c6..798e1e5e 100644
--- a/src/modules/os.c
+++ b/src/modules/os.c
@@ -157,7 +157,7 @@ static bool io_FileIO_read(int argc, py_Ref argv) {
         int actual_size = fread(dst, 1, size, ud->file);
         py_bytes_resize(py_retval(), actual_size);
     } else {
-        void* dst = malloc(size);
+        void* dst = PK_MALLOC(size);
         int actual_size = fread(dst, 1, size, ud->file);
         py_newstrv(py_retval(), (c11_sv){dst, actual_size});
         free(dst);
diff --git a/src/modules/pickle.c b/src/modules/pickle.c
index adebb027..00dfbe33 100644
--- a/src/modules/pickle.c
+++ b/src/modules/pickle.c
@@ -41,7 +41,7 @@ typedef struct {
 
 static void PickleObject__ctor(PickleObject* self) {
     self->used_types_length = pk_current_vm->types.length;
-    self->used_types = malloc(self->used_types_length);
+    self->used_types = PK_MALLOC(self->used_types_length);
     memset(self->used_types, 0, self->used_types_length);
     c11_smallmap_p2i__ctor(&self->memo);
     c11_vector__ctor(&self->codes, sizeof(char));
diff --git a/src/modules/random.c b/src/modules/random.c
index e7c552ae..82bb8212 100644
--- a/src/modules/random.c
+++ b/src/modules/random.c
@@ -225,7 +225,7 @@ static bool Random_choices(int argc, py_Ref argv) {
     if(!py_checktype(py_arg(3), tp_int)) return false;
     py_i64 k = py_toint(py_arg(3));
 
-    py_f64* cum_weights = malloc(sizeof(py_f64) * length);
+    py_f64* cum_weights = PK_MALLOC(sizeof(py_f64) * length);
     if(py_isnone(weights)) {
         for(int i = 0; i < length; i++)
             cum_weights[i] = i + 1;
diff --git a/src/objects/codeobject.c b/src/objects/codeobject.c
index 23a9fa7b..ba90874b 100644
--- a/src/objects/codeobject.c
+++ b/src/objects/codeobject.c
@@ -24,7 +24,7 @@ static void FuncDecl__dtor(FuncDecl* self) {
 }
 
 FuncDecl_ FuncDecl__rcnew(SourceData_ src, c11_sv name) {
-    FuncDecl* self = malloc(sizeof(FuncDecl));
+    FuncDecl* self = PK_MALLOC(sizeof(FuncDecl));
     self->rc.count = 1;
     self->rc.dtor = (void (*)(void*))FuncDecl__dtor;
     CodeObject__ctor(&self->code, src, name);
diff --git a/src/objects/namedict.c b/src/objects/namedict.c
index a221171b..0b258981 100644
--- a/src/objects/namedict.c
+++ b/src/objects/namedict.c
@@ -35,14 +35,14 @@ void ModuleDict__set(ModuleDict* self, const char* key, py_TValue val) {
         if(self->left) {
             ModuleDict__set(self->left, key, val);
         } else {
-            self->left = malloc(sizeof(ModuleDict));
+            self->left = PK_MALLOC(sizeof(ModuleDict));
             ModuleDict__ctor(self->left, key, val);
         }
     } else if(cmp > 0) {
         if(self->right) {
             ModuleDict__set(self->right, key, val);
         } else {
-            self->right = malloc(sizeof(ModuleDict));
+            self->right = PK_MALLOC(sizeof(ModuleDict));
             ModuleDict__ctor(self->right, key, val);
         }
     } else {
diff --git a/src/public/internal.c b/src/public/internal.c
index debd5bcb..286d6a40 100644
--- a/src/public/internal.c
+++ b/src/public/internal.c
@@ -64,7 +64,7 @@ void py_finalize() {
 void py_switchvm(int index) {
     if(index < 0 || index >= 16) c11__abort("invalid vm index");
     if(!pk_all_vm[index]) {
-        pk_current_vm = pk_all_vm[index] = malloc(sizeof(VM));
+        pk_current_vm = pk_all_vm[index] = PK_MALLOC(sizeof(VM));
         memset(pk_current_vm, 0, sizeof(VM));
         VM__ctor(pk_all_vm[index]);
     } else {
diff --git a/src/public/py_dict.c b/src/public/py_dict.c
index c5523506..655e457e 100644
--- a/src/public/py_dict.c
+++ b/src/public/py_dict.c
@@ -78,7 +78,7 @@ typedef struct {
 static void Dict__ctor(Dict* self, uint32_t capacity, int entries_capacity) {
     self->length = 0;
     self->capacity = capacity;
-    self->indices = malloc(self->capacity * sizeof(DictIndex));
+    self->indices = PK_MALLOC(self->capacity * sizeof(DictIndex));
     memset(self->indices, -1, self->capacity * sizeof(DictIndex));
     c11_vector__ctor(&self->entries, sizeof(DictEntry));
     c11_vector__reserve(&self->entries, entries_capacity);
@@ -154,7 +154,7 @@ __RETRY:
 }
 
 static void Dict__compact_entries(Dict* self) {
-    int* mappings = malloc(self->entries.length * sizeof(int));
+    int* mappings = PK_MALLOC(self->entries.length * sizeof(int));
 
     int n = 0;
     for(int i = 0; i < self->entries.length; i++) {
@@ -442,7 +442,7 @@ static bool dict_copy(int argc, py_Ref argv) {
     new_dict->length = self->length;
     new_dict->entries = c11_vector__copy(&self->entries);
     // copy indices
-    new_dict->indices = malloc(new_dict->capacity * sizeof(DictIndex));
+    new_dict->indices = PK_MALLOC(new_dict->capacity * sizeof(DictIndex));
     memcpy(new_dict->indices, self->indices, new_dict->capacity * sizeof(DictIndex));
     return true;
 }
diff --git a/src/public/py_exception.c b/src/public/py_exception.c
index 21fe7560..90e9c2c6 100644
--- a/src/public/py_exception.c
+++ b/src/public/py_exception.c
@@ -218,7 +218,7 @@ char* py_formatexc() {
     }
 
     c11_string* res = c11_sbuf__submit(&ss);
-    char* dup = malloc(res->size + 1);
+    char* dup = PK_MALLOC(res->size + 1);
     memcpy(dup, res->data, res->size);
     dup[res->size] = '\0';
     c11_string__delete(res);